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Natural Science Physical Science Physics Chemistry Earth and Space Science Geology Astronomy Meteorology Life Science Botany Ecology Oceanography Natural science covers a very broad range of knowledge. Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 4 Zoology Genetics Basic Safety Rules Use common sense. No unauthorized experiments. No horseplay. Handle chemicals/glassware with respect. Safety Features of the Lab safety shower fire blanket fire extinguisher eye wash fume hood circuit breaker switch Government Regulation worker OSHA environment EPA The government regulates chemicals to protect the… FDA USDA FAA CPSC consumer DANGER Laboratory Safety Rules Chemical Exposure acute exposure a one-time exposure causes damage chronic exposure damage occurs after repeated exposure Toxicity Which is more toxic? Chemical A: LD50 = 3.2 mg/kg Chemical B: LD50 = 48 mg/kg Chemical A is more toxic because less of it proves fatal to half of a given population. The Functions of Science pure science applied science the search for knowledge; facts using knowledge in a practical way ? Pure Science The search for facts about the natural world. - In science, we often try to establish a cause-effect relationship. - Driven by curiosity: the need to know, explore, conquer something new. Applied Science The practical application of scientific discoveries. -Also known as “technology” - Used to improve our lives Cell phones Biodegradable garbage bags Using the scientific method requires that one be a good observer. observation uses the five senses inference involves a judgment or assumption Data Observations are also called data. There are two types of data. qualitative data quantitative data descriptions; no numbers measurements; must have numbers Parts of the Scientific Method • Identify an unknown. • Make a hypothesis (a testable prediction). • Experiment to test the hypothesis. • Draw a valid conclusion. A Scientific Experiment procedure the order of events in an experiment; the “recipe” variable any factor that could influence the result Experiments must be controlled; they must have two set-ups that must differ by only one variable. The conclusion must be based on the data. A Controlled Experiment? Scientific Law vs. Scientific Theory A law states what happens. Law of Gravity A theory tries to explain why or how something happens. Theory of Gravity Atomic Theory Collision Theory of Reactions Make observation Scientific Method Ask question Develop hypothesis Test hypothesis with further experiments Test hypothesis with an experiment Revise hypothesis Analyze data and draw conclusions Hypothesis IS supported Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 8 Hypothesis is NOT supported Develop theory Phlogiston Theory Phlogiston theory of burning (a) When an object burns it gives off a substance called phlogiston. (b) When the space surrounding the burning object is filled with phlogiston, the object will no longer be able to burn. Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 4 (a) (b) phlogiston phlogiston Combustion Theory Modern theory of burning (c) When an object burns, it uses up a substance (oxygen) in the surrounding space. (d) When the space surrounding the burning object has too little oxygen in it, the object will no longer be able to burn. Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 4 Antoine Lavoiser (c) (d) oxygen Laboratory Equipment transmutation changing one substance into another Philosopher‟s Stone COPPER GOLD In ordinary chemical reactions, we cannot transmute elements into different elements. Alchemy • After that 'chemistry' was ruled by alchemy. • They believed that that could take any cheap metals and turn them into gold. • Alchemists were almost like magicians. – elixirs, physical immortality Alchemy (~500 – 1300 A.D.) the quest for the Philosopher‟s Stone It was supposed to change cheap metals into gold. Alchemical symbols for substances… .. . ...... . ..... GOLD SILVER COPPER IRON SAND transmutation: changing one substance into another In ordinary chemistry, we cannot transmute elements. Contributions of alchemists: lab apparatus / procedures how to make some alloys properties of some elements Government Regulation of Chemicals …to protect the… environment EPA consumer Consumer Product Safety Commission, USDA, BATF, FDA worker OSHA The Scope of Chemistry -- petroleum products gasoline, oil, diesel fuel, heating oil, asphalt -- synthetic fibers nylon, polyester, rayon, spandex -- pharmaceuticals medicines, cancer drugs, VIAGRA 1 in 10,000 new products gets FDA approval -- bulk chemical manufacturing #1 chemical = sulfuric acid (H2SO4) All fields of endeavor are affected by chemistry. Elements of a “good” line graph • axes labeled, with units • use the available space • title • neat Volume (L) Temp. v. Vol. for a Gas at Constant Pressure 10 9 8 7 6 5 4 3 2 1 0 120 140 160 180 200 Temp. (K) 220 240 How to read a graph • • • • Interpolate - read between data points What volume would the gas occupy at a temperature of 150 K? 7 L Extrapolate - read data beyond data points What volume would the gas occupy at a temperature of 260 K? ~4 L Which do you have more confidence in? Why? Volume (L) • (dependent variable) Temp. v. Vol. for a Gas at Constant Pressure 10 9 8 7 6 5 4 3 2 1 0 120 140 160 180 200 Temp. (K) (independent variable) 220 240 Graphs • Line Graph – Used to show trends or continuous change • Bar Graph 80 60 – Used to display information collected by counting 40 20 0 1st 2nd 3r d 4th Qtr Qtr Qtr Qtr • Pie Graph – Used to show how some fixed quantity is broken down into parts Bar Graph Descriptive title Chemistry Grades Number of Students 70 Legend 60 50 A B C D 40 30 20 10 0 1st Qtr Axis labeled (with units) 2nd Qtr 3rd Qtr 4th Qtr How many cm are in 1.32 meters? equality: 1 m = 100 cm (or 0.01 m = 1 cm) applicable conversion factors: ______ 1m 100 cm or ( 100 cm ______ 1m ) 100 cm = 132 cm X cm = 1.32 m ______ 1m We use the idea of unit cancellation to decide upon which one of the two conversion factors we choose. How many feet is 39.37 inches? equality: 1 ft = 12 in applicable conversion factors: ______ 1 ft 12 in X ft = 39.37 in or ______ 12 in 1 ft ( ) ____ 1 ft = 3.28 ft 12 in Again, the units must cancel. How many kilometers is 15,000 decimeters? ( )( 1m X km = 15,000 dm ____ 10 dm ) 1 km ______ = 1.5 km 1,000 m How many seconds is 4.38 days? ( )( 24 h X s = 4.38 d ____ 1d )( ) 60 min _____ 1h 60 s ____ 1 min = 378,432 s If we are accounting for significant figures, we would change this to… 3.78 x 105 s Example Problem Measured dimensions of a rectangle: length (L) = 9.70 cm width (W) = 4.25 cm Find area of rectangle. L A=L.W = (9.70 cm)(4.25 cm) = 41.2 2. cm cm W Convert 41.2 cm2 to mm2. Recall that… 41.2 cm2 = 41.2 cm.cm ( X mm2 = 41.2 cm.cm 10 mm _____ 1 cm )( 1 cm = 4,120 mm2 10 mm _____ ) = 4,120 mm2 ( mm _____ X mm2 = 41.2 cm2 10 1 cm 2 ) Measured dimensions of a rectangular solid: Length = 15.2 cm Width = 3.7 cm Height = 8.6 cm H W Find volume of solid. L V=L.W.H = (15.2 cm)(3.7 cm)(8.6 cm) 3 = 480 cm Convert to m3. cm.cm.cm ( )( 1m X m3 = 480 cm32 _____ 100 cm 1m _____ )( 100 cm ) 1m _____ = 100 cm or 3 ( ) ( 3 1m X m3 = 480 cm3 _____ 100 cm 0.000480 m3 = or X m3 = 480 cm3 ) 1m _________ 4.80 x 10-4 m3 = 1000000 cm3 Convert to m3... Measured dimensions of a rectangular solid: Length = 15.2 cm 0.152 m Width = 3.7 cm 0.037 m Height = 8.6 cm 0.086 m H Find volume of solid. W L V=L.W.H = (0.152 m)(0.037 m)(0.086 m) = 0.000480 m3 Form: (# from 1 to 9.999) x 10exponent 800 = 8 x 10 x 10 = 8 x 102 2531 = 2.531 x 10 x 10 x 10 = 2.531 x 103 0.0014 = 1.4 / 10 / 10 / 10 = 1.4 x 10-3 Change to standard form. 000000187000000 . . 1.87 x 10–5 = 0.0000187 3.7 x 108 = 370,000,000 7.88 x 101 = 78.8 2.164 x 10–2 = 0.02164 Change to scientific notation. 12,340 = 0.369 = 0.008 = 1,000,000,000 = 1.234 x 104 3.69 x 10–1 8 x 10–3 1 x 109 Using the Exponent Key on a Calculator EE EXP EE or EXP means “times 10 to the…” 23:: How out 6.02 6.02 xx 10 1023 How to to type out 6 0 . 2 EE EE 2 3 Don’t do it like this… 6 WRONG! 0 . yx 2 2 3 …or like this… 6 . 0 WRONG! 2 x 1 …or like this: 6 . 0 EE 2 3 TOO MUCH WORK. 0 2 x 1 0 yx 2 3 1.2 x 105 Example: 2.8 x 1013 Type this calculation in like this: 1 . 2 EE 5 2 . 8 EE 1 3 = Calculator gives… 4.2857143 –09 or… 4.2857143 E–09 This is NOT written… 4.3–9 But instead is written… 4.3 x 10–9 or 4.3 E –9 7.5 x 10-6 - 8.7 x 10-4 = -6.525 x 10-9 report -6.5 x 10-9 (2 sig. figs.) 4.35 x 106 1.23 x 10-3 = 5.3505 x 103 or 5350.5 report 5.35 x 103 (3 sig. figs.) 5.76 x 10-16 9.86 x 10-4 = 5.84178499 x 10-13 report 5.84 x 10-13 (3 sig. figs.) 8.8 x 1011 3.3 x 1011 = 2.904 x 1023 report 2.9 x 1023 (2 sig. figs.) 6.022 x 1023 - 5.1 x 10-8 = -3.07122 x 1016 report -3.1 x 1016 (2 sig. figs.) Scientific Notation We often use very small and very large numbers in chemistry. Scientific notation is a method to express these numbers in a manageable fashion. Thus 0.000 000 1 cm can be written 1 x 10-7 cm. Lets see why… Scientific notation expresses a number as the product of two factors, the first falling between 1 and 10 and the second being a power of 10. Converting Numbers to Scientific Notation 0.00002205 1 2 3 4 2.205 x -5 10 5 In scientific notation, a number is separated into two parts. The first part is a number between 1 and 10. The second part is a power of ten. How to Use a Scientific Calculator Divide: (5.44 x 107) .. (8.1 x 104) 07 04 671.604938 5.44 8.100 54400000. How to enter this on a calculator: 5.44 EE 7 .. 8.1 EE 4 ENTER 8.1 EXP 4 = OR 5.44 EXP 7 . . 671.6049383 rounded to 6.7 x 102 Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 52 chemical any substance that takes part in, or occurs as a result of, a chemical reaction All matter can be considered to be chemicals or mixtures of chemicals. chemical reaction a rearrangement of atoms such that “what you end up with” products differs from “what you started with” reactants Combustion of a Hydrocarbon carbon methane + oxygen + water dioxide CH4(g) + 2 O2(g) CO2(g) + 2 H2O(g) sodium + water hydrogen + sodium hydroxide 2 Na(s) + 2 H2O(l) H2(g) + 2 NaOH(aq) Law of Conservation of Mass total mass = total mass of reactants of products Rmass = Pmass synthesis taking small molecules and putting them together, usually in many steps, to make something more complex The International System of Units Quantity Name Length Mass Time Amount of substance Thermodynamic temperature Electric current Luminous intensity meter kilogram second mole Kelvin amperes candela Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 16 Symbol m kg s mol K amps cd The Original Metric Reference H2O 1 kg = 1 liter 1/10,000,000 Earth Volume = 1 meter Length 1/10 m H2O 1/10 m 1/10 m Mass = 1 kilogram Prefixes in the SI System The Commonly Used Prefixes in the SI System Prefix Symbol Meaning Power of 10 for Scientific Notation _______________________________________________________________________ 1,000,000 106 1,000 103 mega- M kilo- k deci- d 0.1 10-1 centi- c 0.01 10-2 milli- m 0.001 10-3 0.000001 10-6 0.000000001 10-9 micro- nano- n Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 118 Instruments for Measuring Volume Graduated cylinder Syringe Buret Pipet Volumetric flask 1024 g 1021 g Quantities of Mass 1018 g 1015 g 1012 g Giga- 109 g Mega- 106 g Kilo- 103 g base 100 g milli- 10-3 g micro- 10-6 g nano- 10-9 g pico- 10-12 g femto- 10-15 g atomo- 10-18 g Ocean liner Indian elephant Average human 1.0 liter of water Grain of table salt 10-21 g 10-24 g Kelter, Carr, Scott, Chemistry A Wolrd of Choices 1999, page 25 Earth‟s atmosphere to 2500 km Typical protein Uranium atom Water molecule SI-US Conversion Factors Relationship Conversion Factors Length 2.54 cm = 1 in. 2.54 cm 1 in and 1 m = 39.4 in. 39.4 in 1m and 946 mL = 1 qt 946 mL 1 qt and 1 qt 946 mL 1 L = 1.06 qt 1.06 qt 1L and 1L 1.06 qt and 1 lb 454 g and 1 kg 2.20 lb 1 in 2.54 cm 1m 39.4 in. Volume Mass 454 g = 1 lb 1 kg = 2.20 lb 454 g 1 lb 2.20 lb 1 kg Accuracy vs. Precision Good accuracy Good precision Poor accuracy Good precision Poor accuracy Poor precision Systematic errors: reduce accuracy (instrument) Random errors: reduce precision (person) Accuracy Precision Resolution time offset [arbitrary units] 3 not accurate, not precise accurate, not precise not accurate, precise accurate and precise accurate, low resolution 2 1 0 -1 -2 -3 subsequent samples SI Prefixes kilodecicentimilli- 1000 1/ 10 1/ 100 1/ 1000 Also know… 1 mL = 1 cm3 and 1 L = 1 dm3 SI System for Measuring Length The SI Units for Measuring Length Unit Symbol Meter Equivalent _______________________________________________________________________ 1,000 m or 103 m kilometer km meter m 1 decimeter dm 0.1 m or 10-1 m centimeter cm 0.01 m or 10-2 m millimeter mm 0.001 m or 10-3 m micrometer m 0.000001 m or 10-6 m nanometer nm 0.000000001 m or 10-9 m Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 118 m or 100 m Practice Measuring Timberlake, Chemistry 7th Edition, page 7 0 cm 1 2 3 4 5 4.5 cm 0 cm 1 2 3 4 5 4.54 cm 0 cm 1 2 3 4 5 3.0 cm 20 ? 15 ?1 mL 1.50 15.0 xmL 10 mL 10 The Importance of Units Units must be carried into the answer, unless they cancel. 5.2 kg (2.9 m) = 0.64 kg-m (18 s)(1.3 s) s2 4.8 kg (23 s) (5.2 s)(37 s) = 0.57 kg s Basic Algebra Solve the following for x. x+y=z x and y are connected by addition. Separate them using subtraction. In general, use opposing functions to separate things. x+y=z –y –y The +y and –y cancel on the left, leaving us with… x=z–y Basic Algebra Solve for x. x and 24 are connected by subtraction. Separate them using the opposite function: addition. x – 24 = 13 x – 24 = 13 +24 +24 The –24 and +24 cancel on the left, leaving us with… x = 37 Basic Algebra Solve for x. x and k are connected by multiplication. Separate them using the opposite function: division. The two k‟s cancel on the left, leaving us with… F=kx () () __ 1 __ 1 F=kx k k (or) F=kx k k __ F x= k Basic Algebra Solve for x. x and 7 are connected by multiplication. Separate them using the opposite function: division. The two 7‟s cancel on the right, leaving us with… 8=7x () () __ 1 __ 1 8=7x 7 7 (or) 8=7x 7 7 __ 8 x= 7 Basic Algebra Solve for x. One way to solve this is to cross-multiply. Then, divide both sides by TR. The answer is… ___ BA = ___ TR x H BAH = xTR ( ) ( ) ___ 1 BAH = xTR ___ 1 TR TR BAH x = ___ TR Solve for T2, where… P 1V1 ____ = P1 = 1.08 atm T1 P2 = 0.86 atm ____ 1 PVT = V1 = 3.22 L 1 1 2 P V 1 1 V2 = 1.43 L P2V2T1 T1 = 373 K ( ) P 2V2 ____ T2 ( ) ____ 1 P1V1 P2V2T1 ______ T2 = P1V1 (0.85 atm)(1.43 L)(373 K) _____________________ T2 = = 130 K (1.08 atm)(3.22 L) A General Procedure for Solving Problems • Read the problem carefully and make a list of the “knowns” and the „unknowns” • Look up all needed information – Your lecture notes will have much, if not all, of the needed information • Work out a plan and, following your plan, obtain an answer by carrying out the required math. • Check over your work – This is best done by estimating your answer – Ask yourself: “Does the answer seem reasonable?” Resources - Intro. to Chemistry Worksheet - vocabulary Worksheet - material safety data sheet (acetone) Activity - checkbook activity Worksheet - graphing Worksheet - real life chemistry Worksheet - conversion factors Worksheet - scientific notation Worksheet - metric article (questions) Worksheet - significant digits Worksheet - math review Worksheet - math of chemistry Worksheet - article on the metric system Outline (general) Energy and Matter Unit 2 Physical and Chemical Properties Examples of Physical Properties Boiling point Color Slipperiness Electrical conductivity Melting point Taste Odor Dissolves in water Shininess (luster) Softness Ductility Viscosity (resistance to flow) Volatility Hardness Malleability Density (mass / volume ratio) Examples of Chemical Properties Burns in air Reacts with certain acids Decomposes when heated Explodes Reacts with certain metals Reacts with certain nonmetals Tarnishes Reacts with water Is toxic Ralph A. Burns, Fundamentals of Chemistry 1999, page 23 Chemical properties can ONLY be observed during a chemical reaction! Three Possible Types of Bonds Covalent e.g. H2 + - Polar Covalent + - Ionic e.g. HCl e.g. NaCl Metallic Bonding Cations + e1+ e1- + + e1+ e1e1- + e1- “electron sea” + e1- + + + e1- e1- e1+ Free electrons e1- e1- + e1- + e1- e1- + e1- Metallic bonding is the attraction between positive ions and surrounding freely mobile electrons. Most metals contribute more than one mobile electron per atom. Bailar, Jr, Moeller, Kleinberg, Guss, Castellion, Metz, Chemistry, 1984, page 245 Shattering an Ionic Crystal; Bending a Metal broken crystal An ionic crystal Force + + + + - + + + + - + + + + - + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + - + - + A metal Force + + - - + - + - + - + + + + + + + + + + + + - + + + + - + + + + - + + + + + + + + + + + + + + + + + + - + + + + + + + + + + + + + Electrostatic forces of repulsion + + + + + + + + + + + + + + + + + + + + + + No electrostatic forces of repulsion – metal is deformed (malleable) Bailar, Jr, Moeller, Kleinberg, Guss, Castellion, Metz, Chemistry, 1984, page 248 Covalent vs. Ionic Alike Different Share electrons Different Transfer electrons Chemical Bonds (polar vs. nonpolar) (ions formed) +/- Topic Between Two Nonmetals Covalent Topic Electrons are involved Ionic Between Metal and Nonmetal Weak Bonds Strong Bonds (low melting point) (high melting point) Temperature Scales Boiling point of water Fahrenheit Celcius Kelvin 212 oF 100 oC 373 K 180 oF Freezing point of water 32 oF 100 oC 0 oC 100 K 273 K Notice that 1 kelvin degree = 1 degree Celcius Heat versus Temperature lower temperature Fractions of particles higher temperature TOTAL = Heat Kinteic ENERGY Kinetic energy Temperature vs. Heat Different Alike Measured with a Thermometer Have Kinetic Energy Topic Average Kinetic Energy oCelcius (or Kelvin) Temperature Different Measured with a Calorimeter Topic A Property of Matter Heat Total Kinetic Energy Joules (calories) Conservation of Matter Reactants yield Products It appears that the brick is ~40x more dense than the styrofoam. Styrofoam ? Brick Which liquid has the highest density? least dense 1 < 3 < 5 < 2 1 3 2 Coussement, DeSchepper, et al. , Brain Strains Power Puzzles 2002, page 16 5 4 < 4 most dense Volume and Density Relationship Between Volume and Density for Identical Masses of Common Substances Substance Cube of substance (face shown actual size) Mass (g) Volume (cm3) 19 Density (g.cm3) Lithium 10 0.53 Water 10 10 1.0 Aluminum 10 3.7 2.7 Lead 10 0.58 11.4 Density D = M V M M = DxV ass D ensity V olume V = M D Consider Equal Volumes Mass Density = Volume Equal volumes… …but unequal masses The more massive object (the gold cube) has the GREATER _________ density. aluminum Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 71 gold Consider Equal Masses Equal masses… …but unequal volumes. aluminum The object with the larger volume (aluminum cube) has the smaller density. Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 71 gold Specific Gravity cork 0.25 0.9 aluminum 2.7 Jaffe, New World of Chemistry, 1955, page 66 ice water 1.0 Tank of Water Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 143 Person Submerged in Water Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 143 Archimedes Principle Thread Vfinal = 98.5 cm3 - Vinitial = 44.5 cm3 Vfishing sinker = 54.0 cm3 98.5 cm3 44.5 cm3 Fishing sinker Water Before immersion After immersion Dissolving of Salt in Water Na+ ions Water molecules Clions NaCl(s) + H2O Na+(aq) + Cl-(aq) Some Properties of Solids, Liquids, and Gases Property Solid Liquid Gas Shape Has definite shape Takes the shape of the container Takes the shape of its container Volume Has a definite volume Has a definite volume Fills the volume of the container Arrangement of Particles Fixed, very close Random, close Random, far apart Interactions between particles Very strong Strong Essentially none Energy Changes Accompanying Phase Changes Gas Energy of system Vaporization Condensation Sublimation Liquid Melting Freezing Solid Brown, LeMay, Bursten, Chemistry 2000, page 405 Deposition Heating Curve for Water Temperature (oC) E D 100 C liquid B 0 A solid Heat added LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 487 gas Heating Curve for Water Temperature (oC) vaporization D 100 condensation melting C liquid B 0 A solid freezing Heat added LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 487 E gas MATTER yes MIXTURE yes Is the composition uniform? Homogeneous Mixture (solution) PURE SUBSTANCE no Heterogeneous Mixture Colloids no Can it be physically separated? yes Can it be chemically decomposed? Compound Suspensions Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem no Element Pure Substances Element – composed of identical atoms – EX: copper wire, aluminum foil Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Pure Substances Compound – composed of 2 or more elements in a fixed ratio – properties differ from those of individual elements – EX: table salt (NaCl) Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Pure Substances Law of Definite Composition – A given compound always contains the same, fixed ratio of elements. Law of Multiple Proportions – Elements can combine in different ratios to form different compounds. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Mixtures Variable combination of 2 or more pure substances. Heterogeneous Homogeneous Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Mixtures Solution – homogeneous – very small particles – no Tyndall effect Tyndall Effect – particles don‟t settle – EX: rubbing alcohol Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Mixtures Colloid – heterogeneous – medium-sized particles – Tyndall effect – particles don‟t settle – EX: milk Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Mixtures Suspension – heterogeneous – large particles – Tyndall effect – particles settle – EX: fresh-squeezed lemonade Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Classification of Matter Materials Homogeneous Heterogeneous Substance Element Compound Homogeneous mixture Solution Order / Disorder Smoot, Smith, Price, Chemistry A Modern Course, 1990, page 43 Heterogeneous mixture Mixture Classification of Matter MATTER (gas. Liquid, solid, plasma) Separated by PURE SUBSTANCES MIXTURES physical means into Separated by COMPOUNDS ELEMENTS chemical means into Kotz & Treichel, Chemistry & Chemical Reactivity, 3rd Edition , 1996, page 31 HOMOGENEOUS MIXTURES HETEROGENEOUS MIXTURE Elements, Compounds, and Mixtures hydrogen atoms oxygen atoms (a) an element (hydrogen) (b) a compound (water) hydrogen atoms Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 68 (c) a mixture (hydrogen and oxygen) (d) a mixture (hydrogen and oxygen) Mixture vs. Compound Different Alike Variable Composition Involve substances Topic No bonds between components Can be separated by physical means Mixture Different Fixed Composition Topic Contain two or more elements Can be separated into elements Compound Bonds between components Can ONLY be separated by chemical means Allotropes of Carbon Graphite Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 27 Diamond Buckminsterfullerene Gold Gold Copper Silver 24 karat gold 24/ 24 atoms Au 18 karat gold 18/ 24 atoms Au 14 karat gold 14/ 24 atoms Au An alloy is a mixture of metals. • Brass = Copper + Zinc • Solid brass • homogeneous mixture Copper Zinc Solid Brass • Brass = Copper + Zinc • Brass plated • heterogeneous mixture • Only brass on outside Copper Zinc Brass Plated Methods of Separating Mixtures • • • • • • • Magnet Filter Decant Evaporation Centrifuge Chromatography Distillation Mixture of solid and liquid Filtration separates a liquid from a solid Stirring rod Funnel Filter paper traps solid Filtrate (liquid component of the mixture) Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 40 Chromatography • Tie-dye t-shirt • Black pen ink • DNA testing – Tomb of Unknown Soldiers – Crime scene – Paternity testing Setup to heat a solution Ring stand Beaker Wire gauze Ring Bunsen burner Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 42 A Distillation Apparatus thermometer liquid with a solid dissolved in it condenser tube distilling flask Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 282 hose connected to cold water faucet receiving flask pure liquid The solution is boiled and steam is driven off. Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 39 Salt remains after all water is boiled off. Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 39 No chemical change occurs when salt water is distilled. Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 40 Centrifugation • Spin sample very rapidly: denser materials go to bottom (outside) • Separate blood into serum and plasma – Serum (clear) – Plasma (contains red blood cells „RBCs‟) AFTER Before Serum Blood RBC’s • Check for anemia (lack of iron) A B C Water Molecules Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 8 The decomposition of two water molecules. Water molecules Diatomic oxygen molecule + Diatomic hydrogen molecules Electric current 2 H2O O2 + 2 H2 Electrolysis “electro” = electricity “lysis” = to split H2O(l) water *H1+ Water Oxygen gas forms Hydrogen gas forms O2 (g) + 2 H2 (g) oxygen hydrogen *Must add acid catalyst to conduct electricity Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 32 Source of direct current Electrode if molecules collide with enough force to break them into atoms, a ELEMENT CHEMICAL REACTION can take place hydrogen molecule, H2 COMPOUND MIXTURE ELEMENT oxygen molecule, O2 a mixture of hydrogen and oxygen molecules water, H2O Energy A C B Kinetic Energy – energy of motion KE = ½ m v 2 mass velocity (speed) Potential Energy – stored energy Batteries (chemical potential energy) Spring in a watch (mechanical potential energy) Water trapped above a dam (gravitational potential energy) Kinetic Energy and Reaction Rate lower temperature Fractions of particles higher temperature minimum energy for reaction Kinetic energy Kinetic Energy and Reaction Rate lower temperature Fractions of particles higher temperature minimum energy for reaction Kinetic energy Decomposition of Nitrogen Triiodide Decomposition of Nitrogen Triiodide N2 NI3 2 NI3(s) I2 N2(g) + 3 I2(g) Exothermic Reaction Reactants Products + Energy 10 energy = 8 energy + 2 energy Energy of reactants Energy Energy of products Reactants - H Products Reaction Progress Endothermic Reaction Energy + Reactants Products Energy Activation Energy Reactants Products + H Endothermic Reaction progress Effect of Catalyst on Reaction Rate WhatCatalyst is a catalyst? does it do duringfor a chemical reaction? lowers What the activation energy the reaction. No catalyst Energy activation energy for catalyzed reaction reactants products Reaction Progress Energy Sources in the United States 100 91 Percent 80 71 70 60 50 40 40 20 58 50 21 9 26 20 5 10 3 21 26 16 10 0 1850 Wood 1900 Coal Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 307 1940 1980 Petroleum / natural gas 1990 2005 Hydro and nuclear Energy Conversion fan electrical energy to mechanical energy light bulb electrical energy to light energy to thermal and radiant energy pencil sharpner electrical energy to mechanical energy Timberlake, Chemistry 7th Edition, page 202 coffee maker electrical energy to thermal energy Burning of a Match Potential energy System Surroundings (Reactants) (PE) Energy released to the surrounding as heat (Products) Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 293 Conservation of Energy in a Chemical Reaction In this example, the energy Endothermic of the reactants Reaction and products increases, while the energy of the surroundings decreases. Reactant + Energy Product In every case, however, the total energy does not change. Surroundings Energy Surroundings System System Myers, Oldham, Tocci, Chemistry, 2004, page 41 Before reaction After reaction Conservation of Energy in a Chemical Reaction In this example, the energy Exothermic of the reactants Reaction and products decreases, while the energy of the surroundings increases. Reactant Product + Energy In every case, however, the total energy does not change. Energy Surroundings Myers, Oldham, Tocci, Chemistry, 2004, page 41 System Before reaction Surroundings System After reaction Heating Curves 140 120 Gas - KE Temperature (oC) 100 80 Boiling - PE 60 40 20 0 -20 Liquid - KE Melting - PE -40 -60 -80 Solid - KE -100 Time Calculating Energy Changes Heating Curve for Water 140 120 H = mol x Hfus H = mol x Hvap Temperature (oC) 100 80 Heat = mass x t x Cp, gas 60 40 20 0 Heat = mass x t x Cp, liquid -20 -40 -60 -80 Heat = mass x t x Cp, solid -100 Time Endothermic Reaction Energy + Reactants Products Energy Activation Energy Reactants Products + H Endothermic Reaction progress Fission vs. Fusion Different Alike Split large atoms U-235 Change Nucleus of Atoms Topic Radioactive waste (long half-life) Nuclear Power Plants Fission Different Fuse small atoms 2H2 He Topic Create Large Amounts of Energy E = mc2 Transmutation of Elements Occurs Fusion NO Radioactive waste Very High Temperatures ~5,000,000 oC (SUN) Nuclear Fission First stage: 1 fission Second stage: 2 fission Third stage: 4 fission Half-life of Radiation Radioisotope remaining (%) Initial amount of radioisotope 100 After 1 half-life After 2 half-lives 50 After 3 half-lives t1/2 25 t1/2 12.5 t1/2 0 1 2 3 Number of half-lives 4 Resources - Matter and Energy Objectives - matter and energy Objectives - measurement Objectives - phases of matter Worksheet - vocabulary Activity - chromatography Worksheet - percentage composition Outline - causes of change - calorimetry Worksheet - properties Worksheet - calorimetry problems 1 Worksheet - density problems Worksheet - calorimetry problems 2 Activity - density blocks & Part 2 Worksheet - heat energy problems Lab - golf ball lab Worksheet - conversion factors Worksheet - classifying matter Worksheet - atoms, mass, and the mole Article - buckeyball & questions (video) activity - mole pattern Article - buried in ice (questions) Lab - beverage density (PowerPoint) Outline (general) Atomic Structure Unit 3 Greek Model “To understand the very large, we must understand the very small.” Democritus • Greek philosopher • Idea of „democracy‟ • Idea of „atomos‟ – Atomos = „indivisible‟ – „Atom‟ is derived • No experiments to support idea • Continuous vs. discontinuous theory of matter Democritus’s model of atom No protons, electrons, or neutrons Solid and INDESTRUCTABLE Four Element Theory FIRE • Plato was an atomist • Thought all matter was composed of 4 elements: – – – – – Earth (cool, heavy) Water (wet) Fire (hot) Air (light) Ether (close to heaven) Hot Dry „MATTER‟ AIR Wet EARTH Cold WATER Relation of the four elements and the four qualities Blend these “elements” in different proportions to get all substances Foundations of Atomic Theory Law of Conservation of Mass Mass is neither destroyed nor created during ordinary chemical reactions. Law of Definite Proportions The fact that a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound. Law of Multiple Proportions If two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first elements is always a ratio of small whole numbers. Conservation of Atoms 2 H2 + O 2 2 H 2O John Dalton H H H2 O H O2 + H2 H O H 2O O H 2O H H O H H 4 atoms hydrogen 2 atoms oxygen Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 204 4 atoms hydrogen 2 atoms oxygen Dalton‟s Symbols John Dalton 1808 Daltons‟ Models of Atoms Carbon dioxide, CO2 Water, H2O Methane, CH4 Dalton‟s Atomic Theory 1. All matter is made of tiny indivisible particles called atoms. 2. Atoms of the same element are identical, those of different atoms are different. 3. Atoms of different elements combine in whole number ratios to form compounds 4. Chemical reactions involve the rearrangement of atoms. No new atoms are created or destroyed. California WEB Crookes Tube William Crookes Crookes tube (Cathode ray tube) Glow Cathode (-) Anode (+) http://encarta.msn.com/media_461556463_761559903_-1_1/Crookes_Tube.html Mask holder Crooke‟s Tube - voltage source William Crookes + vacuum tube metal disks magnet A Cathode Ray Tube Source of Electrical Potential Stream of negative particles (electrons) Metal Plate Gas-filled glass tube Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 58 Metal plate A Cathode Ray Tube Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 58 The Effect of an Obstruction on Cathode Rays High voltage source of high voltage shadow cathode yellow-green fluorescence Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 117 The Effect of an Electric Field on Cathode Rays source of high voltage High voltage cathode negative plate _ + anode positive plate Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 117 William Thomson (Lord Kelvin) • In 1910 proposed the Plum Pudding model – Negative electrons were embedded into a positively charged spherical cloud. Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 56 Spherical cloud of Positive charge Electrons Rutherford‟s Apparatus beam of alpha particles radioactive substance fluorescent screen circular - ZnS coated gold foil Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 120 Geiger Counter Ionization of fill gas takes place along track of radiation (-) (+) Speaker gives “click” for each particle Metal tube (negatively charged) Window + e- e+ + + ee- Ionizing radiation path Atoms or molecules of fill gas Wilbraham, Staley, Matta, Waterman, Chemistry, 2002, page 857 Central wire electrode (positively charged) Free e- are attracted to (+) electrode, completing the circuit and generating a current. The Geiger counter then translates the current reading into a measure of radioactivity. Interpreting the Observed Deflections . . . . . . beam of alpha particles . . . . . undeflected particles . . . . . gold foil Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 120 . deflected particle Explanation of Alpha-Scattering Results Alpha particles Nucleus + + - - + + - + + - + - + - - Plum-pudding atom Nuclear atom Thomson‟s model Rutherford‟s model Results of foil experiment if plumpudding had been correct. Electrons scattered throughout - + - positive charges + + + + - - + + + - Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 57 - Interpreting the Observed Deflections deflected particle . . . . . . beam of alpha particles . . . . . . . . . . gold foil Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 120 . undeflected particles Bohr Atom The Planetary Model of the Atom Models of the Atom "In science, a wrong theory can be valuable and better than no theory at all." - Sir William L. Bragg e e + e + e + + e +e + e e + e + e Dalton‟s Greek model model (400 (1803) B.C.) Thomson‟s plum-pudding model (1897) Bohr‟s model (1913) Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 125 - - + Rutherford‟s model (1909) Charge-cloud model (present) Models of the Atom e e + e - + e + + e +e +e e + e + e Dalton‟s model Greek model (1803) (400 B.C.) 1803 John Dalton pictures atoms as tiny, indestructible particles, with no internal structure. 1800 - Thomson‟s plum-pudding model (1897) - + Rutherford‟s model (1909) 1897 J.J. Thomson, a British 1911 New Zealander scientist, discovers the electron, leading to his "plum-pudding" model. He pictures electrons embedded in a sphere of positive electric charge. Ernest Rutherford states that an atom has a dense, positively charged nucleus. Electrons move randomly in the space around the nucleus. 1805 ..................... 1895 1900 1905 1910 1904 Hantaro Nagaoka, a Japanese physicist, suggests that an atom has a central nucleus. Electrons move in orbits like the rings around Saturn. Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 125 1915 Bohr‟s model (1913) 1926 Erwin Schrodinger 1913 In Niels Bohr's model, the electrons move in spherical orbits at fixed distances from the nucleus. 1920 1925 Charge-cloud model (present) 1930 develops mathematical equations to describe the motion of electrons in atoms. His work leads to the electron cloud model. 1935 1940 1945 1924 Frenchman Louis 1932 James de Broglie proposes that moving particles like electrons have some properties of waves. Within a few years evidence is collected to support his idea. Chadwick, a British physicist, confirms the existence of neutrons, which have no charge. Atomic nuclei contain neutrons and positively charged protons. An unsatisfactory model for the hydrogen atom According to classical physics, light should be emitted as the electron circles the nucleus. A loss of energy would cause the electron to be drawn closer to the nucleus and eventually spiral into it. Hill, Petrucci, General Chemistry An Integrated Approach 2nd Edition, page 294 Discovery of the Neutron 9 4 Be + 4 2 He 12 6 C + 1 0 n James Chadwick bombarded beryllium-9 with alpha particles, carbon-12 atoms were formed, and neutrons were emitted. Dorin, Demmin, Gabel, Chemistry The Study of Matter 3rd Edition, page 764 17 Cl 35.453 • Assume you have only two atoms of chlorine. • One atom has a mass of 35 amu (Cl-35) • The other atom has a mass of 36 amu (Cl-36) • What is the average mass of these two isotopes? 35.5 amu • Looking at the average atomic mass printed on the periodic table...approximately what percentage is Cl-35 and Cl-36? 55% Cl-35 and 45% Cl-36 is a good approximation 17 Cl 35.453 Using our estimated % abundance data 55% Cl-35 and 45% Cl-36 calculate an average atomic mass for chlorine. Average Atomic Mass = (% abundance of isotope "A")(mass "A") + (% "B")(mass "B") + ... AAM = (% abundance of isotope Cl-35)(mass Cl-35) + (% abundance of Cl-36)(mass Cl-36) AAM = (0.55)(35 amu) + (0.45)(36 amu) AAM = (19.25 amu) + (16.2 amu) AAM = 35.45 amu Particles in the Atom Electrons (-) charge no mass located outside the nucleus 1 amu located inside the nucleus 1 amu located inside the nucleus Protons (+) charge Neutron no charge Structure of the Atom There are two regions The nucleus • With protons and neutrons – Positive charge – Almost all the mass Electron cloud – Most of the volume of an atom – The region where the electron can be found Subatomic Particles ATOM ATOM NUCLEUS NUCLEUS ELECTRONS ELECTRONS PROTONS PROTONS NEUTRONS NEUTRONS POSITIVE Positive CHARGE Charge NEUTRAL Neutral CHARGE Charge NEGATIVE CHARGE Negative Charge equal in a Atomic Most Number of the atom‟s mass. neutral atom equals the # of... QUARKS Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Symbols Contain the symbol of the element, the mass number and the atomic number # protons + # neutrons mass number # protons Mass number Atomic number X Symbols • Find the – number of protons = 9 + – number of neutrons = 10 – number of electrons = 9 – Atomic number = 9 – Mass number = 19 19 9 F Symbols Find the – number of protons = 35 – number of neutrons = 45 – number of electrons = 35 – Atomic number = 35 – Mass number = 80 80 35 Br Symbols Find the – number of protons – number of neutrons – number of electrons – Atomic number – Mass number 23 11 Na Sodium atom Symbols Find the – number of protons = 11 – number of neutrons = 12 – number of electrons = 10 – Atomic number = 11 – Mass number = 23 23 11 1+ Na Sodium ion Symbols If an element has an atomic number of 23 and a mass number of 51 what is the – number of protons = 23 – number of neutrons = 28 – number of electrons = 23 – Complete symbol 51 23 V Symbols If an element has 60 protons and 84 neutrons what is the – Atomic number = 60 = 144 – Mass number – number of electrons = 60 – Complete symbol 144 60 Nd Symbols If a neutral atom of an element has 78 electrons and 117 neutrons what is the – Atomic number = 78 – Mass number = 195 – number of protons = 78 – Complete symbol 195 78 Pt Mass Number • mass # = protons + neutrons • always a whole number Neutron + • NOT on the Periodic Table! Electrons Nucleus + + + + + Nucleus Carbon-12 Neutrons 6 Protons 6 Electrons 6 Proton Isotopes • Atoms of the same element with different mass numbers. • Nuclear symbol: Mass # Atomic # 12 6 • Hyphen notation: carbon-12 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem C Isotopes Neutron + Electrons Nucleus + + + + + Nucleus Proton Proton Nucleus Carbon-12 Neutrons 6 Protons 6 Electrons 6 + + + + Neutron Electrons + + Carbon-14 Neutrons 8 Protons 6 Electrons 6 Nucleus Measuring Atomic Mass • Unit is the Atomic Mass Unit (amu) • One twelfth the mass of a carbon-12 atom. • Each isotope has its own atomic mass we need the average from percent abundance. (1 amu) (1 amu) (1 amu) (1 amu) carbon atom (1 amu) (1 amu) (1 amu) (1 amu) (12 amu) (1 amu) (1 amu) (1 amu) (1 amu) Atomic Mass Magnesium has three isotopes. 78.99% magnesium 24 with a mass of 23.9850 amu, 10.00% magnesium 25 with a mass of 24.9858 amu, and the rest magnesium 26 with a mass of 25.9826 amu. What is the atomic mass of magnesium? If not told otherwise, the mass of the isotope is the mass number in amu. California WEB Isotope Percent Abundance Mass Mg-24 78.99 23.9850 18.94575 Mg-25 10.00 24.9585 2.49585 Mg-26 11.01 25.9826 2.86068 24.304 amu Atomic Mass Calculate the atomic mass of copper if copper has two isotopes. 69.1% has a mass of 62.93 amu and the rest has a mass of Percent 64.93 amu. Isotope Mass Abundance Cu-63 69.1 62.93 43.48463 Cu-65 30.9 64.93 20.06337 63.548 Average atomic mass (AAM) (% " A" )(mass " A" ) (% " B" )(mass " B" ) ... A.A.M. (0.691)(62.93 amu) (0.309)(64.93 amu) A.A.M. 43.48463 amu 20.06337 amu A.A.M. 63.548 amu for Copper 29 Cu 63.548 Protons Neutrons Electrons Mass number Cu-65 A B 29 C A. B. C. Argon D E F 40 D. E. F. Ba2+ 56 G H I G. H. I. Given the average atomic mass of an element is 118.21 amu and it has three isotopes (“A”, “B”, and “C”): isotope “A” has a mass of 117.93 amu and is 87.14% abundant isotope “B” has a mass of 120.12 amu and is 12.36% abundant Find the mass of isotope “C”. Show work for credit. Extra Credit: What is a cation? Protons Neutrons Electrons Mass number Cu-65 A = 29 B = 36 29 C = 65 Argon D = 18 E = 22 F = 18 40 Ba2+ 56 G = 81 H = 54 I = 137 Given the average atomic mass of an element is 118.21 amu and it has three isotopes (“A”, “B”, and “C”): isotope “A” has a mass of 117.93 amu and is 87.14% abundant isotope “B” has a mass of 120.12 amu and is 12.36% abundant Find the mass of isotope “C”. Show work for credit. 119.7932 amu Extra Credit: What is a cation? A positively charged atom. An atom that has lost a(n) electron(s). Maximum Capacities of Subshells and Principal Shells n 1 2 l 0 0 1 0 1 2 0 1 2 3 Subshell designation s s p s p d s p d f Orbitals in subshell 1 1 3 1 3 5 1 3 5 7 Subshell capacity 2 2 6 2 6 10 2 6 10 14 Principal shell capacity 2 8 Hill, Petrucci, General Chemistry An Integrated Approach 1999, page 320 3 18 4 ...n 32 ...2n 2 Electron Configurations Orbital Filling Element 1s 2s 2px 2py 2pz 3s Electron Configuration H 1s1 He 1s2 C NOT CORRECT 1s22s1 Violates Hund‟s Rule 1s22s22p2 N 1s22s22p3 O 1s22s22p4 F 1s22s22p5 Ne 1s22s22p6 Na 1s22s22p63s1 Li Electron Configurations Orbital Filling Element 1s 2s 2px 2py 2pz 3s Electron Configuration H 1s1 He 1s2 Li 1s22s1 C 1s22s22p2 N 1s22s22p3 O 1s22s22p4 F 1s22s22p5 Ne 1s22s22p6 Na 1s22s22p63s1 Filling Rules for Electron Orbitals Aufbau Principle: Electrons are added one at a time to the lowest energy orbitals available until all the electrons of the atom have been accounted for. Pauli Exclusion Principle: An orbital can hold a maximum of two electrons. To occupy the same orbital, two electrons must spin in opposite directions. Hund‟s Rule: Electrons occupy equal-energy orbitals so that a maximum number of unpaired electrons results. *Aufbau is German for “building up” Filling Rules for Electron Orbitals Aufbau Principle: Electrons are added one at a time to the lowest energy orbitals available until all the electrons of the atom 6s 6p 5d 4f have been accounted for. 32 5s 5p 4d 18 Pauli Exclusion Principle: An orbital can hold a maximum of two electrons. 4s 4p 3d To occupy the same orbital, two electrons must spin in opposite 18 directions. Arbitrary North South 3s 3p Energy Scale 8 - - 2s 2p Hund‟s Rule: Electrons occupy equal-energy orbitals so that a maximum number of unpaired electrons results. 8 1s *Aufbau is German for “building up” S N NUCLEUS 2 Maximum Number of Electrons In Each Sublevel Maximum Number of Electrons In Each Sublevel Sublevel Number of Orbitals Maximum Number of Electrons s 1 2 p 3 6 d 5 10 f 7 14 LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 146 Order in which subshells are filled with electrons 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 2 2 6 2 6 2 10 6 2 10 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d … 4f Sublevels 4d Energy 6d 5f 7s 6p 5d 4f 6s 5p 4d 5s 4p 3d 4s 3p 6d 7s 6p 5d 6s 4f n=3 5p 4p 3d 4s 3p 3s 4d 5s 4p 3d 4s 3p 3s 2p 2s 5f Energy n=4 2p 3s 2p n=2 2s 2s 1s 1s n=1 1s 4f Sublevels 4d s p s d p s n=4 f d p Energy s n=3 4p 3d 4s 3p 3s 1s22s22p63s23p64s23d104p65s24d10… 2p n=2 2s n=1 1s Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p 4f Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Hydrogen 4f Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La H = 1s1 Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Helium 4f Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La He = 1s2 Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Lithium 4f Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La Li = 1s22s1 Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Carbon 4f Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La C = 1s22s22p2 Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Nitrogen 4f Bohr Model N Hund’s Rule “maximum number of unpaired orbitals”. 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La N = 1s22s22p3 Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Fluorine 4f Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La F = 1s22s22p5 Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Aluminum 4f Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La Al = 1s22s22p63s23p1 Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Argon 4f Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La Ar = 1s22s22p63s23p6 Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p Iron 4f Bohr Model N 2s 2p 1s Electron Configuration Fe = 1s22s22p63s23p64s23d6 NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS Fe La Arbitrary Energy Scale Energy Level Diagram 6s 6p 5d 5s 5p 4d 4s 4p 3d 3s 3p 4f Lanthanum Bohr Model N 2s 2p 1s Electron Configuration NUCLEUS H He Li C N Al Ar F CLICK ON ELEMENT TO FILL IN CHARTS La = 1s22s22p63s23p64s23d10 Fe La 4s23d104p65s24d105p66s25d1 Shorthand Configuration A neon's electron configuration (1s22s22p6) B third energy level [Ne] 3s1 C D one electron in the s orbital orbital shape Na = [1s22s22p6] 3s1 electron configuration Shorthand Configuration Element symbol Electron configuration Ca [Ar] 4s2 V [Ar] 4s2 3d3 F [He] 2s2 2p5 Ag [Kr] 5s2 4d9 I [Kr] 5s2 4d10 5p5 Xe [Kr] 5s2 4d10 5p6 Fe Sg 22p64s [He] 2s[Ar] 3s223d 3p664s23d6 [Rn] 7s2 5f14 6d4 General Rules 6d Aufbau Principle 7s 6p 5d – Electrons fill the lowest energy orbitals first. 6s 4d 3p 5f 7s 6p 5d 6s 5p 5s 4p 4s 6d 4f 5p Energy – “Lazy Tenant Rule” 5f 4d 5s 3d 4p 3d 4s 3p 3s 3s 2p 2p 2s 2s 1s 1s Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem 4f General Rules • Hund‟s Rule – Within a sublevel, place one electron per orbital before pairing them. – “Empty Bus Seat Rule” WRONG RIGHT Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem 8 O Notation 15.9994 • Orbital Diagram O 8e- 1s 2s • Electron Configuration 2 2 4 1s 2s 2p Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem 2p 16 Notation S 32.066 • Longhand Configuration S 16e- 1s2 2s2 2p6 3s2 3p4 Core Electrons Valence Electrons • Shorthand Configuration S 16e 2 4 [Ne] 3s 3p Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Periodic Patterns s 1 2 3 4 5 6 7 p 1s 2s f 2p 3s d (n-1) 3p 4s 3d 4p 5s 4d 5p 6s 5d 6p 7s 6d 7p 6 (n-2) 7 4f 5f 1s Periodic Patterns • Example - Hydrogen 1 2 3 4 5 6 7 1 1s 1st Period 1st column of s-block s-block Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Periodic Patterns • Shorthand Configuration – Core electrons: • Go up one row and over to the Noble Gas. – Valence electrons: • On the next row, fill in the # of e- in each sublevel. 1 2 3 4 5 6 7 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem 32 Periodic Patterns • Example - Germanium 1 2 3 4 5 6 7 [Ar] 2 4s 10 3d Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem 2 4p Ge 72.61 Electron Filling in Periodic Table s s p 1 2 d 3 4 K 4s1 Ca 4s2 Sc 3d1 Ti 3d2 4f Energy n=4 n=3 V 3d3 Cr 3d54 Mn 3d5 Fe 3d6 Co 3d7 Ni 3d8 Cu 9 3d 3d10 Cr Cu 4s13d5 4s13d10 Zn 3d10 Ga 4p1 Ge 4p2 As 4p3 Se 4p4 Br 4p5 Kr 4p6 4d 4p 3d 4s 3p 3s Cr 4s13d5 4s 3d 2p n=2 2s n=1 Cu 1s 4s13d10 4s 3d Stability • Ion Formation – Atoms gain or lose electrons to become more stable. – Isoelectronic with the Noble Gases. 1 2 3 4 5 6 7 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Stability • Ion Electron Configuration – Write the e- config for the closest Noble Gas – EX: Oxygen ion O2- 10e- O2- Ne [He] 2s2 2p6 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem 28 Orbital Diagrams for Nickel 1s 2 2s 2 6 2p 3s 2 6 3p 2 4s 3d 8 Excited State 1s 2 2s 2 2p 6 3s 2 3p6 4s1 3d 9 Pauli Exclusion 1s 2s 2p 3s 3p 4s 3d Hund‟s Rule 1s 2s 2p 3s 3p 4s 3d Ni 58.6934 28 Orbital Diagrams for Nickel 1s 2 2s 2 6 2p 3s 2 6 3p 2 4s 3d 8 Excited State 1s 2 2s 2 2p 6 3s 2 3p6 4s1 3d 9 VIOLATES Pauli Exclusion 1s 2s 2p 3s 3p 4s 3d VIOLATES Hund‟s Rule 1s 2s 2p 3s 3p 4s 3d Ni 58.6934 Write out the complete electron configuration for the following: 1) An atom of nitrogen 2) An atom of silver POP QUIZ 3) An atom of uranium (shorthand) Fill in the orbital boxes for an atom of nickel (Ni) 1s 2s 2p 3s 3p 4s 3d Which rule states no two electrons can spin the same direction in a single orbital? Extra credit: Draw a Bohr model of a Ti4+ cation. Ti4+ is isoelectronic to Argon. Answer Key Write out the complete electron configuration for the following: 1) An atom of nitrogen 1s22s22p3 1s22s22p63s23p64s23d104p65s24d9 2) An atom of silver 3) An atom of uranium (shorthand) [Rn]7s26d15f3 Fill in the orbital boxes for an atom of nickel (Ni) 1s 2s 2p 3s 3p 4s 3d Which rule states no two electrons can spin the same direction in a single orbital? Pauli exclusion principle Extra credit: Draw a Bohr model of a Ti4+ cation. Ti4+ is isoelectronic to Argon. n= 22+ n Electron Configurations of First 18 Elements: Hydrogen Helium 1H 2He Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon 3Li 4Be 5B 6C 7N 8O 9F 10Ne Sodium Magnesium Aluminum Silicon Phosphorous Sulfur Chlorine Argon 11Na 12Mg 13Al 14Si 15P 16S 17Cl 18Ar Electron Dot Diagrams Group 1A 2A 3A 4A 5A 6A 7A H 8A He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ga Ge As Se Br Kr s1 s2 s2p1 s2p2 s2p3 s2p4 = valence electron s2p5 s2p6 Metals and Nonmetals 1 2 3 H He 1 2 Li Be B C 3 4 5 Na Mg 11 4 K 19 5 7 Ca Sc O F Ne 6 7 8 9 10 Al Si P S Cl Ar 13 14 15 16 17 18 Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 23 24 35 36 I Xe 53 54 20 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In 39 40 41 42 49 Hf Ta W 72 73 74 37 6 12 N 38 Cs Ba 55 56 Fr Ra 87 88 Nonmetals 25 26 27 28 29 30 METALS 43 44 Re Os 75 76 47 45 46 Ir Pt Au Hg Tl 77 78 81 79 48 31 80 32 33 34 Sn Sb Te 50 51 Pb Bi 82 83 52 Po At Rn 84 85 86 Rf Db Sg Bh Hs Mt 104 105 106 107 108 Metalloids 109 La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 57 58 59 Ac Th Pa 89 90 91 60 U 92 61 62 63 64 65 66 Np Pu Am Cm Bk Cf 93 94 95 96 97 98 67 68 69 70 71 Es Fm Md No Lr 99 100 101 102 103 Metals, Nonmetals, & Metalloids 1 Nonmetals 2 3 4 5 Metals 6 7 Metalloids Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 349 Isotopes of Magnesium 12e- 12e12p+ 12n0 Atomic symbol 24 12 Mg 12p+ 13n0 25 12 Mg 12e12p+ 14n0 26 12 Mg Number of protons 12 12 12 Number of electrons 12 12 12 Mass number 24 25 26 Number of neutrons 12 13 14 Mg-24 Mg-25 Mg-26 Isotope Notation Timberlake, Chemistry 7th Edition, page 64 Isotopes of Hydrogen Protium 1 p+ Deuterium 1 e- 1 H 1 (ordinary hydrogen) H-1 Ralph A. Burns, Fundamentals of Chemistry 1999, page 100 1 p+ 1n 2 H 1 (heavy hydrogen) H-2 Tritium 1 e- 1 p+ 2n 3 1 1 e- H (radioactive hydrogen) H-3 Isotopes of Three Common Elements Mass Element Carbon Chlorine Silicon Symbol Mass (amu) Fractional Abundance Number 12 6 C 12 12 (exactly) 99.89% 13 6 C 13 13.003 1.11% 35 17 Cl 35 34.969 75.53% 37 17 Cl 37 36.966 24.47% 28 29 30 27.977 28.976 29.974 28 14 29 14 Si Si 30 Si 14 LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 110 92.21% 4.70% 3.09% Average Atomic Mass 12.01 35.45 28.09 Atomic Structure • ATOMS – Differ by number of protons • IONS – Differ by number of electrons • ISOTOPES – Differ by number of neutrons Formation of Cation sodium atom Na sodium ion Na+ ee- e- e- e- e- ee- e- 11p+ ee- loss of one valence electron e- e- 11p+ e- e- ee- e- e- ee- Formation of Anion chlorine atom Cl e- egain of one valence electron ee- e- e- chloride ion Cl1e- eee- e- e- e- e- ee- e- 17p+ 17p+ e- e- e- e- ee- e- e- ee- ee- e- e- eee- e- e- Formation of Ionic Bond chloride ion Cl1- sodium ion Na+ e- e- ee- e- e- e- e- e- ee- e- 11p+ e- e- e- e- e- e- 17p+ e- ee- e- e- e- ee- e- e- Ionic Bonding NaCl n=3 - n=2 n=3 - - - - - - - Na [Ne]3s1 - - - + - - - - - - - - - Cl [Ne]3s23p5 - - - Na+ [Ne] - - - Cl[Ne]3s23p6 Transfer of electrons to achieve a stable octet (8 electrons in valence shell). Covalent Bonding n=2 - - - - n=1 - - - - + - - - - - - - - - - - - - O [He]2s22p4 - O [He]2s22p4 O2 Sharing of electrons to achieve a stable octet (8 electrons in valence shell). Review - Development of Atom Model e e + e e + + e +e +e e + e + e Dalton‟s model Greek model (1803) (400 B.C.) - + Thomson‟s plum-pudding model (1897) - - + Rutherford‟s model (1909) Bohr‟s model (1913) Charge-cloud model (present) Neils Bohr •planetary model of atom •electrons in fixed "orbit" •energy level = ring on atom J.J. Thomson Democratus (Greek) •cathode ray tube experiment •bowling ball •discovered electrons and protons •no experiments _ •mental model •term "atomos" = indivisible Ernest Rutherford •discontinuos theory of matter •gold foil experiment + •atom mostly empty space •nucleus (small & (+) charge) William Thomson (Lord Kelvin) •alpha particles (+) charged •proposed "plum-pudding" model •Geiger counter to detect radiation •ZnS coated screen John Dalton •bowling ball •based on experimental evidence •law of conservation of mass - Lavoisier •law of definite proportions - Proust •law of multiple proportions •NO protons, NO electrons, NO neutrons •Atom should collapse Quantum-Mechanical Model Developed by many scientists: Albert Einstein Erwin Schrodinger (math) Louis DeBroglie (wave nature) Werner Heisenberg (probability) Max Planck (quanta) •s, p, d, f-orbitals •based on probability •Heisenberg Uncertainty principle •quantum mechanics (math) Cl2 a molecule of chlorine e- Cl1- a chloride ion Cl an atom of chlorine 2Cl NaCl (an anion) two atoms of chlorine a compound of sodium chloride 27 Co 58.9332 Co-60 ISOTOPES Co-59 a) element symbol b) mass of isotope 59 2+ Co 27 p+ = 27 n0 = 33 e- = 27 p+ = 27 n0 = 32 e- = 27 p+ = 27 n0 = 32 e- = 25 Isotopes have different number of... neutrons Ions have different number of... electrons 1 Nonmetals 2 3 M M N + 3e- e- M+ + 2e- + M2+ N3- 4 Metals form CATIONS 5 Metals 6 Nonmetals form ANIONS 7 Metalloids 16 Orbital Diagram for Sulfide Ion S 32.066 sulfur atom 1s 2 2s 2 6 2p 3s 2 4 3p 4s 3d S = 1s22s22p63s23p4 sulfide ion (gain 2 electrons) 1s 2 2s 2 S + 2e- 2p 6 3s S2- 2 6 3p 4s 3d S2- = 1s22s22p63s23p6 argon atom 1s 2s 2p 3s 3p 4s Ar = 1s22s22p63s23p6 3d Resources - Atomic Structure Objectives Worksheet - vocabulary Worksheet - development of atomic theory Worksheet - atomic number and mass number Worksheet - ions and subatomic particles Lab - isotopes Worksheet - orbital diagrams Worksheet - electron configuration Worksheet - light problems Worksheet - half-life Outline (general) Aliens Activity Nautilus shell has a repeating pattern. Look carefully at the drawings of the „aliens‟. Organize all the aliens into a meaningful pattern. Prelab Aliens Lab Cards Periodic Table Alkaline earth metals H 1 2 3 4 5 6 7 8A He Alkali metals 1A Transition metals 3A 4A 5A 6A 7A B C N O F 1 2A Boron group Li Be Nonmetals 3 4 Na Mg 11 12 K Ca 19 20 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In 37 38 39 40 41 42 49 Cs Ba Hf Ta W 55 56 72 73 74 Fr Ra 87 88 Noble gases 5 Al 8B 3B 4B 5B 6B 7B 1B 2B Sc Ti V Cr Mn Fe Co Ni Cu Zn 23 24 25 26 43 27 44 Re Os 75 76 28 29 30 47 13 45 46 48 Ir Pt Au Hg Tl 77 78 81 79 80 7 8 9 10 Si P S Cl Ar 14 15 16 17 18 As Se Br Kr 33 32 Sn Sb 50 51 Pb Bi 82 83 34 35 36 Te I Xe 52 53 54 At Rn 85 86 Po 84 Rf Db Sg Bh Hs Mt 104 105 106 107 108 109 Lanthanoid Series 6 C Br Liquid H La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 57 Solid 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Actinoid Series 7 Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Gas 89 90 91 92 93 94 95 96 97 98 99 Ne 6 Ga Ge 31 2 100 101 102 103 Döbereiner‟s Triads Johann Döbereiner ~1817 Name Atomic Mass Name Atomic Mass Name Atomic Mass Calcium Barium 40 137 Chlorine Iodine 35.5 127 Sulfur Tellurium 32 127.5 Average 88.5 Average 81.3 Average 79.8 Strontium 87.6 Bromine 79.9 Selenium 79.0 Döbereiner discovered groups of three related elements which he termed a triad. Smoot, Price, Smith, Chemistry A Modern Course 1987, page 161 Newland‟s Law of Octaves John Newlands ~1863 Newland‟s Law of Octaves 1 2 3 4 5 6 7 Li Na K Be Mg B Al C Si N P O S F Cl Smoot, Price, Smith, Chemistry A Modern Course 1987, page 161 Mendeleev‟s Periodic Table Group I II III IV V VI VII VIII F = 19 Period 1 H=1 2 Li = 7 Be= 9.4 B = 11 C = 12 N = 14 O = 16 F = 19 3 Na = 23 Mg = 24 Al = 27.3 Si = 28 P = 31 S = 32 C = 35.5 4 K = 39 Ca = 40 ? = 44 Ti = 48 V = 51 Cr = 52 Mn = 55 5 Cu = 63 Zn = 65 ? = 68 ? = 72 As = 75 Se = 78 Br = 80 6 Rb = 85 Sr = 87 ? Yt = 88 Zr = 90 Nb = 94 Mo = 96 ? = 100 7 Ag = 108 Cd = 112 In = 113 Sn = 118 Sb = 122 Te = 125 J = 127 8 Cs = 133 Ba = 137 ?Di = 138 ?Ce = 140 ?Er = 178 ?La = 180 Ta = 182 W = 184 Tl = 204 Pb = 207 Bi = 208 Fe =56, Co = 59, Ni = 59 Ru= 104, Rh = 104, Pd = 106 9 10 11 12 Au = 199 Hg = 200 Th = 231 U = 240 Os = 195, Ir = 197, Pt = 198 Elements Properties are Predicted Property Mendeleev‟s Predictions in 1871 Observed Properties Scandium (Discovered in 1877) Molar Mass Oxide formula Density of oxide Solubility of oxide 44 g M2O3 3.5 g / ml Dissolves in acids 43.7 g Sc2O3 3.86 g / ml Dissolves in acids Gallium (Discovered in 1875) Molar mass Density of metal Melting temperature Oxide formula Solubility of oxide 68 g 6.0 g / ml Low M2O3 Dissolves in ammonia solution 69.4 g 5.96 g / ml 30 0C Ga2O3 Dissolves in ammonia Germanium (Discovered in 1886) Molar mass Density of metal Color of metal Melting temperature Oxide formula Density of oxide Chloride formula Density of chloride Boiling temperature of chloride 72 g 5.5 g / ml Dark gray High MO2 4.7 g / ml MCl4 1.9 g / ml Below 100 oC O‟Connor Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 119, 71.9 g 5.47 g / ml Grayish, white 900 0C GeO2 4.70 g / ml GeCl4 1.89 g / ml 86 0C Modern Periodic Table • Henry G.J. Moseley • Determined the atomic numbers of elements from their X-ray spectra (1914) • Arranged elements by increasing atomic number • Killed in WW I at age 28 (Battle of Gallipoli in Turkey) 1887 - 1915 1 2 3 Hydrogen Halogens Alkali metals Noble Gases Alkaline Earth Metals Other Nonmetals Coinage Metals Lanthanides H Other Transition Elements Actinides 1 Metalloids (B, Si, Ge, As, Sb, Te, At) Other metals Be B C N O F Ne 3 4 5 6 7 8 9 10 Al Si P S Cl Ar 13 14 15 16 17 18 Na Mg K 19 5 7 12 Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 23 24 35 36 I Xe 53 54 20 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In 39 40 41 42 49 Hf Ta W 72 73 74 37 6 2 Li 11 4 He 38 Cs Ba 55 56 Fr Ra 87 88 25 43 26 44 Re Os 75 76 27 28 29 47 30 45 46 Ir Pt Au Hg Tl 77 78 81 79 48 31 80 32 33 34 Sn Sb Te 50 51 Pb Bi 82 83 52 Po At Rn 84 85 86 Rf Db Sg Bh Hs Mt 104 105 106 107 108 109 La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 57 58 59 Ac Th Pa 89 90 91 60 U 92 61 62 63 64 65 66 Np Pu Am Cm Bk Cf 93 94 95 96 97 98 67 68 69 70 71 Es Fm Md No Lr 99 100 101 102 103 Metals and Nonmetals 1 2 3 H He 1 2 Li Be B C 3 4 5 Na Mg 11 4 K 19 5 7 Ca Sc O F Ne 6 7 8 9 10 Al Si P S Cl Ar 13 14 15 16 17 18 Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 23 24 35 36 I Xe 53 54 20 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In 39 40 41 42 49 Hf Ta W 72 73 74 37 6 12 N 38 Cs Ba 55 56 Fr Ra 87 88 Nonmetals 25 26 27 28 29 30 METALS 43 44 Re Os 75 76 47 45 46 Ir Pt Au Hg Tl 77 78 81 79 48 31 80 32 33 34 Sn Sb Te 50 51 Pb Bi 82 83 52 Po At Rn 84 85 86 Rf Db Sg Bh Hs Mt 104 105 106 107 108 Metalloids 109 La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 57 58 59 Ac Th Pa 89 90 91 60 U 92 61 62 63 64 65 66 Np Pu Am Cm Bk Cf 93 94 95 96 97 98 67 68 69 70 71 Es Fm Md No Lr 99 100 101 102 103 Properties of Metals, Nonmetals, and Metalloids METALS malleable, lustrous, ductile, good conductors of heat and electricity NONMETALS gases or brittle solids at room temperature, poor conductors of heat and electricity (insulators) METALLOIDS (Semi-metals) dull, brittle, semi-conductors (used in computer chips) Symbols are Useful The use of symbols is not unique to chemistry. Symbols can be quite helpful - when you know what they mean. Arithmetic + - x Money Music ¢ $ ♪♫ ♪♫ : Chemistry Fe + CuSO4 ? mp A Swedish chemist who invented modern chemical symbols. Discovered the elements silicon, selenium, cerium, and thorium. Jons Jakob Berzelius (1799 - 1848) Names and Symbols of Selected Elements Name* Symbol Name* Symbol Aluminum Argon Barium Boron Bromine Cadmium Calcium Carbon Chlorine Cobalt Copper (cuprum) Fluorine Gold (aurum) Helium Hydrogen Iodine Iron (ferrum) Al Ar Ba B Br Cd Ca C Cl Co Cu F Au He H I Fe Lead (plumbum) Lithium Magnesium Mercury (hydrargyrum) Neon Nickel Nitrogen Oxygen Phosphorus Potassium (kalium) Silicon Silver (argentum) Sodium (natrum) Strontium Sulfur Tin (stannum) Zinc Pb Li Mg Hg Ne Ni N O P K Si Ag Na Sr S Sn Zn *Names given in parentheses are ancient Latin or Greek words from which the symbols are derived. Origin of the Names of Elements Title Pre-chemical Names Names from celestial bodies Names from mythology / superstition Names from minerals / ores, other than geographical names Names from colors Names from properties other than color Geographical names from the domicile or workplace of the discoverer(s) Geographical names from minerals / ores Constructed names Names from persons Ringnes, Journal of Chemical Education, Sept. 1989, page 731 Number of Elements 10 8 10 13 9 8 13 10 16 10 The Periodic Table Alkaline earth metals 1 Noble gases Halogens 18 H He 2 13 14 15 16 17 Li Be B C N O F Ne 3 4 5 6 7 8 9 10 Al Si P S Cl Ar 13 14 15 16 17 18 1 3 Na Mg Alkali metals 11 K 19 4 5 6 7 8 9 Transition metals 10 11 12 12 Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 23 24 35 36 I Xe 53 54 20 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In 39 40 41 42 49 Hf Ta W 72 73 74 37 38 Cs Ba 55 56 Fr Ra 87 88 Lanthanides 25 43 26 44 Re Os 75 76 27 28 29 47 30 45 46 Ir Pt Au Hg Tl 77 78 81 79 48 31 80 Rf Db Sg Bh Hs Mt Uun Uuu Uub 104 La 57 Actinides 2 Ac 89 105 106 107 108 109 110 111 112 32 33 34 Sn Sb Te 50 51 Pb Bi 82 83 52 Po At Rn 84 85 86 Uuq Uuh Uuo 113 116 118 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 58 59 60 Th Pa U 90 92 91 61 62 63 64 65 66 Np Pu Am Cm Bk Cf 93 94 95 96 97 98 67 68 69 70 71 Es Fm Md No Lr 99 100 101 102 103 Orbitals Being Filled 1 Periods 1 1s 8 Groups 2 3 4 5 2 2s 2p 3 3s 3p 4 4s 3d 4p 5 5s 4d 5p 6 6s La 5d 6p 7 7s Ac 6d Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 345 6 7 1s 4f Lanthanide series 5f Actinide series Electron Filling in Periodic Table s p 1 2 3 d 4 5 6 7 f s Electron Filling in Periodic Table metallic character increases nonmetallic character increases metallic character increases nonmetallic character increases Periodic Table s 1 s H p H He 1 2 1 2 3 Li Be B C N O F Ne 3 4 5 6 7 8 9 10 Al Si P S Cl Ar 13 14 15 16 17 18 Na Mg 11 4 K 19 5 7 12 Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 23 24 35 36 I Xe 53 54 20 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In 39 40 41 42 49 Hf Ta W 72 73 74 37 6 d 38 Cs Ba 55 56 Fr Ra 87 88 25 43 26 44 Re Os 75 76 27 28 29 30 47 48 31 45 46 Ir Pt Au Hg Tl 77 78 81 79 80 32 33 34 Sn Sb Te 50 51 Pb Bi 82 83 52 Po At Rn 84 85 86 Rf Db Sg Bh Hs Mt 104 105 106 107 108 109 f La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 57 58 59 Ac Th Pa 89 90 91 60 U 92 61 62 63 64 65 66 Np Pu Am Cm Bk Cf 93 94 95 96 97 98 67 68 69 70 71 Es Fm Md No Lr 99 100 101 102 103 Melting Points 1 H Mg -259.2 2 3 4 Li Be 180.5 1283 650 K Ca Sc Rb Sr 38.8 6 > 3000 98 850 770 710 B oC 2000 - 3000 oC Al 660 Ti V C N O F Y 1500 1852 2487 2610 2127 2427 1966 1550 920 Ta P 1423 44.2 420 29.78 960 Zr Nb Mo Tc Ru Rh Pd Ag Cd Hf Si S 119 Ne W Re Os Ir 961 In Ar -101 -189.6 Kr 817 217.4 -7.2 -157.2 Sn Sb Te I Xe 321 156.2 231.9 630.5 450 113.6 -111.9 Pt Au Hg Tl Pb Bi Po At Rn 2222 2997 3380 3180 2727 2454 1769 1063 -38.9 303.6 327.4 271.3 254 Ralph A. Burns, Fundamentals of Chemistry , 1999, page 1999 Cl Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br 1423 1677 1917 1900 1244 1539 1495 1455 1083 Cs Ba La 28.6 -269.7 2027 4100 -210.1 -218.8 -219.6 -248.6 Na Mg 63.2 5 650 He Symbol Melting point oC -71 Densities of Elements 1 2 3 4 H He 0.071 0.126 Li Be B C N O 0.53 1.8 2.5 2.26 0.81 1.14 Na Mg Al Si P S 0.97 2.70 2.4 1.82w 2.07 1.557 1.402 K 0.86 5 Ca Sc Ti V 1.55 4.5 5.96 Rb Sr (2.5) 2.6 I Xe 4.93 3.06 7.86 8.9 8.90 8.92 7.14 5.91 5.36 5,7 4.7 6.4 8.4 10.2 8.6 7.3 7.3 Cs Ba La Hf Ta W Pt Au Hg Tl Pb Bi 1.90 13.1 16.6 19.3 8.0 – 11.9 g/cm3 Mg 1.74 Ar 3.119 7.4 5.51 6.7 Cl 7.1 Sn Sb Te 3.5 1.11 1.204 Kr In 2.6 Y Ne Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Zr Nb Mo Tc Ru Rh Pd Ag Cd 1.53 6 1.74 F 11.5 12.5 Re Os 12.5 Ir 12.0 10.5 21.4 22.48 22.4 21.45 19.3 13.55 11.85 11.34 12.0 – 17.9 g/cm3 6.7 9.8 6.1 Po At Rn 9.4 > 18.0 g/cm3 Symbol Density in g/cm3C, for gases, in g/L --- 4.4 1 H H He 1 2 1 2 3 Li Be B C N O F Ne 3 4 5 6 7 8 9 10 Al Si P S Cl Ar 13 14 15 16 17 18 Na Mg 11 4 K 19 5 7 Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 23 24 35 36 I Xe 53 54 20 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In 39 40 41 42 49 Hf Ta W 72 73 74 37 6 12 38 Cs Ba 55 56 Fr Ra 87 88 25 43 26 44 Re Os 75 76 27 28 29 47 30 45 46 Ir Pt Au Hg Tl 77 78 81 79 48 31 80 32 33 34 Sn Sb Te 50 51 Pb Bi 82 83 52 Po At Rn 84 85 86 Rf Db Sg Bh Hs Mt 104 105 106 107 108 109 La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 57 58 59 Ac Th Pa 89 90 91 60 U 92 61 62 63 64 65 66 Np Pu Am Cm Bk Cf 93 94 95 96 97 98 67 68 69 70 71 Es Fm Md No Lr 99 100 101 102 103 e Ir O N Mn 77 1 8 7 25 H H He 1 2 1 2 3 Li Be B C N O F Ne 3 4 5 6 7 8 9 10 Al Si P S Cl Ar 13 14 15 16 17 18 Na Mg 11 4 K 19 5 7 Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 23 24 35 36 I Xe 53 54 20 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In 39 40 41 42 49 Hf Ta W 72 73 74 37 6 12 38 Cs Ba 55 56 Fr Ra 87 88 25 43 26 44 Re Os 75 76 27 28 29 47 30 45 46 Ir Pt Au Hg Tl 77 78 81 79 48 31 80 32 33 34 Sn Sb Te 50 51 Pb Bi 82 83 52 Po At Rn 84 85 86 Rf Db Sg Bh Hs Mt 104 105 106 107 108 109 La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 57 58 59 Ac Th Pa 89 90 91 60 U 92 61 62 63 64 65 66 Np Pu Am Cm Bk Cf 93 94 95 96 97 98 67 68 69 70 71 Es Fm Md No Lr 99 100 101 102 103 Electron Filling in Periodic Table s s 1 H p H He 1s1 1s2 1s1 2 3 4 5 6 7 Li Be B C N O F Ne 2s1 2s2 2p1 2p2 2p3 2p4 2p5 2p6 Al Si P S Cl Ar 3p1 3p2 3p3 3p4 3p5 3p6 Na Mg d 3s1 3s2 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 4s1 4s2 3d1 3d2 3d3 3d5 3d10 4p1 4p2 4p5 4p6 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 5s1 4d1 4d2 4d4 4d5 4d6 4d7 4d8 4d10 4p1 5p1 5p2 5p5 5p6 Cs Ba Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 6s1 6s2 5d2 5d3 5d4 5d5 5d7 5d9 6p1 6p2 6p4 Fr Ra Rf Db Sg Bh Hs Mt 7s1 7s2 6d2 5s2 6d3 6d4 3d5 6d5 3d6 5d6 6d6 3d7 3d8 3d10 4d10 5d10 5d10 4p3 5p3 6p3 4p4 5p4 6p5 6p6 6d7 f La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 5d1 4f2 4f3 4f4 Ac Th Pa U 6d1 5f3 6d2 5f2 4f5 4f6 4f7 4f7 4f9 4f10 Np Pu Am Cm Bk Cf 5f4 5f6 5f7 5f7 5f8 5f10 4f11 4f12 4f13 4f14 4f114 Es Fm Md No Lr 5f11 5f14 5f13 5f14 5f14 Electronegativities 1A 1 Period 2 3 4 5 6 7 8A H 2.1 2A 3A 4A 5A 6A 7A Li Be B C N O F 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Al Si P S Cl 1.5 1.8 2.1 2.5 3.0 Na Mg 1.2 3B 4B 5B 6B K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br 0.8 1.0 1.3 1.5 1.6 1.6 1.7 1.6 1.8 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te 0.8 1.2 1.4 1.6 1.8 1.9 2.2 2.2 2.2 1.7 1.7 1.8 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At 0.7 0.9 1.3 1.5 1.7 1.9 2.2 2.2 1.8 1.8 2.0 Fr Ra Ac 0.7 0.9 1.0 1.1 1.1 8B 7B 1.5 1.8 2.2 1.8 1B 2B 0.9 1.8 1.9 1.9 2.4 1.9 2.0 1.9 1.9 2.4 2.1 Lanthanides: 1.1 - 1.3 Actinides: 1.3 - 1.5 Hill, Petrucci, General Chemistry An Integrated Approach 2nd Edition, page 373 Below 1.0 2.0 - 2.4 1.0 - 1.4 2.5 - 2.9 1.5 - 1.9 3.0 - 4.0 2.8 I 2.5 2.2 Diatomic Molecules Hydrogen (H2) atomic radius = 37 pm Distance between nuclei Nucleus Chlorine (Cl2) atomic radius = 99 pm Fluorine (F2) atomic radius = 64 pm Bromine (Br2) atomic radius = 114 pm Atomic radius Oxygen (O2) atomic radius = 66 pm Nitrogen (N2) atomic radius = 71 pm HOBrFINCl twins Iodine (I2) atomic radius = 138 pm H2 O2 Br2 F2 I2 N2 Cl2 Atomic Radii IA IIA IIIA IVA VA VIA VIIA Li Be B C N O F 1.52 1.11 0.88 0.77 0.70 0.66 0.64 Na Mg Al Si P S Cl 1.86 1.60 1.43 1.17 1.10 1.04 0.99 K Ca Ga Ge As Se Br 2.31 1.97 1.22 1.22 1.21 1.17 1.14 Rb Sr In Sn Sb Te I 2.44 2.15 1.62 1.40 1.41 1.37 1.33 Cs Ba Tl Pb Bi 2.62 2.17 1.71 1.75 1.46 = 1 Angstrom Atomic Radii of Representative Elements (nm) 1A 2A 3A 4A 5A 6A 7A Li Be B C N O F 0.1.52 0.111 0.088 0.077 0.070 0.066 0.064 Na Mg Si P S Cl 0.186 0.160 0.143 0.117 0.110 0.104 0.099 Ca Ga Ge As Se Br 0.197 0.122 0.122 0.121 0.117 0.114 Rb Sr In Sn Sb Te I 0.244 0.215 0.162 0.140 0.141 0.137 0.133 Cs Ba Tl Pb Bi Po 0.262 0.217 0.171 0.175 0.146 0.140 K 0.231 Al LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 175 At 0.140 Shielding Effect Valence (screening effect) + nucleus - Kernel electrons block the attractive force of the nucleus from the valence electrons - Electron Shield “kernel” electrons Electrons Shielding Effect and Effective Nuclear Charge 12 Mg 24.305 attractions repulsions + _ _ _ Mg = [Ne]3s2 Hill, Petrucci, General Chemistry An Integrated Approach 2nd Edition, page 336 Atomic Radius of Atoms Be B C N O F Na Mg Al Si P S Cl K Ca Ga Ge As Se Br Rb Sr In Sn Sb Te I Cs Ba Tl Pb Bi Attraction and Repulsion of Electrical Charges + - Particles with unlike charges attract one another. - - + Particles with like charges repel one another. + Coulombic Attraction A 1+ 1- D B C 2+ 2+ 2- 4- 3- Coulombic Attraction 2- 1) Charge opposites attract like repels 2) Distance Atomic Ionic Radii Radii IA IIA IIIA IVA Li1+ Li VA VIA Be2+ Be B C NN3- OO2- F1F 1.52 0.60 1.11 0.31 0.88 0.77 0.70 1.71 0.66 1.40 0.64 1.36 1+ Na Na Mg2+ Mg Al3+ Al Si P 1.43 0.50 1.17 1.10 1.04 1.84 0.99 1.81 2SS VIIA 1ClCl 1.86 0.95 1.60 0.65 K K1+ Ca Ca2+ Ga3+ Ge As Se2Se Br1Br 2.31 1.33 1.97 0.99 1.22 0.62 1.22 1.21 1.17 1.98 1.14 1.85 Rb Rb1+ Sr Sr2+ In3+ In Sn Sb 2.44 1.48 2.15 1.13 1.62 0.81 1.40 1.41 Tl3+ Tl Pb Bi 1.71 0.95 1.75 1.46 Cs Cs1+ Ba Ba2+ 2.62 1.69 2.17 1.35 2TeTe 1.37 2.21 II11.33 2.16 = 1 Angstrom Atomic Radii IA IIA IIIA IVA VA VIA VIIA Li Be B C N O F 1.52 1.11 0.88 0.77 0.70 0.66 0.64 Na Mg Al Si P S Cl 1.86 1.60 1.43 1.17 1.10 1.04 0.99 K Ca Ga Ge As Se Br 2.31 1.97 1.22 1.22 1.21 1.17 1.14 Rb Sr In Sn Sb Te I 2.44 2.15 1.62 1.40 1.41 1.37 1.33 Cs Ba Tl Pb Bi 2.62 2.17 1.71 1.75 1.46 = 1 Angstrom Ionic Radii IA IIA Li1+ Be2+ 0.60 0.31 Na1+ Mg2+ 0.95 0.65 K1+ Ca2+ 1.33 0.99 IIIA Sr2+ 1.48 1.13 VA VIA VIIA N3- O2- F1- 1.71 1.40 1.36 S2- Cl1- 1.84 1.81 Ga3+ Se2- Br1- 0.62 1.98 1.85 Al3+ 0.50 In3+ Rb1+ IVA 0.81 Te22.21 I12.16 Tl3+ Cs1+ Ba2+ 1.69 1.35 0.95 = 1 Angstrom Trends in Atomic and Ionic Size Metals Nonmetals Group 1 Group 13 Group 17 e e Li+ Li 152 F 64 60 e e Na+ Na 95 e e 136 e Al3+ Al 143 F- 50 Cl Cl- 99 186 181 e e K+ Br K 227 133 Cations are smaller than parent atoms 114 Br195 Anions are larger than parent atoms e Li+ Li 152 60 e e Li+ e Li Li + e Lithium ion 152 Lithium atom 152 Lithium atom 60 IA Atomic Radii Li 1.52 Na 1.86 IVA Be B C 0.88 0.77 Al Si 1.60 1.43 1.17 Ca 1.97 Ga Ge 1.22 Sr 1.11 Mg VA VIA VIIA N O F 0.70 P 0.66 S 0.64 Cl 1.04 0.99 As Se Br 1.22 1.21 1.17 1.14 In Sn Sb Te 2.15 1.62 1.40 1.41 I 1.33 Ba Tl Pb Bi 2.62 2.17 1.71 1.75 1.46 Li1+ Be2+ 2.31 Rb 2.44 Cs 0.60 Na1+ 0.31 0.95 0.65 K1+ Cations: smaller than parent atoms IIIA 1.10 K Ionic Radii IIA Mg2+ Ca2+ N31.71 Al3+ 0.50 Ga3+ 1.33 Rb1+ 0.99 Sr2+ 0.62 1.48 Cs1+ 1.13 Ba2+ 0.81 Tl3+ 1.69 1.35 0.95 In3+ 1.37 O21.40 F11.36 S21.84 Cl11.81 Se2- Br1- 1.98 1.85 Te2- I1- 2.21 2.16 = 1 Angstrom Anions: LARGER than parent atoms The Octet Rule and Common Ions - - 8+ - - - - Oxygen atom O 2 1s 2s22p4 +2e- - - - - 9+ - - - - 10+ - - - - 11+ - - Fluorine atom F 2 1s 2s22p5 Neon atom Ne 2 1s 2s22p6 Sodium atom Na 2 1s 2s22p63s1 +1e- -1e- - - - 12+ - Magnesium atom Mg 2 1s 2s22p63s2 -2e- 8+ - - 9+ - - - - 11+ - - - - 12+ - - Oxygen ion O21s22s22p6 Fluorine ion F11s22s22p6 Sodium ion Na1+ 1s22s22p6 Magnesium ion Mg2+ 1s22s22p6 - Isoelectronic Species Isoelectronic - all species have the same number of electrons. p=8 n=8 e = 10 p=9 n=9 e = 10 p = 10 n = 10 e = 10 p = 11 n = 11 e = 10 p = 12 n = 12 e = 10 8+ - - 9+ - - - - 10+ - - - - 11+ - - - - 12+ - - Oxygen ion O21s22s22p6 Fluorine ion F11s22s22p6 Neon atom Ne 2 1s 2s22p6 Sodium ion Na1+ 1s22s22p6 Magnesium ion Mg2+ 1s22s22p6 - - Can you come up with another isoelectronic series of five elements? Ionization Energy Hungry for Tater Tots? Mr. C at 7 years old. OUCH!! Ionization Energies 18 Group 1 1 Period 2 3 H 6 7 13 14 15 16 17 B C N O F 2 Li Be 520 900 801 Na Mg Al Si 578 787 738 12 S Cl Ar 590 633 659 651 906 579 762 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te 403 600 640 652 684 702 868 558 709 Cs Ba La Hf Ta W Re Os Pt Au Hg Tl Pb Bi Po At Rn 376 503 659 761 770 760 868 589 716 812 Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Uuu Uub Uut Uuq Uup -- 509 538 490 -- Lanthanide series -- 1012 1000 1251 1521 Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br 653 -- 717 -- 762 710 839 -- 760 720 Ir 878 -- 737 804 -- 746 731 890 -- 1007 -- -- -- 947 834 703 941 869 Kr 1140 1351 I Xe 1008 1170 -- 1038 Uuo -- -- Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 534 Actinide series 11 P V 550 10 1086 1402 1314 1681 2081 Ti 7 9 Ne Ca Sc K 3 8 2372 5 738 6 First Ionization Energy (kJ/mol) 4 419 5 He Symbol 1312 496 4 Mg 527 Th Pa 587 570 533 U 598 536 545 547 592 566 573 581 589 597 603 523 Np Pu Am Cm Bk Cf Es Fm Md No Lr 600 619 585 578 581 601 608 627 635 642 -- First Ionization Energies (in kilojoules per mole) H He 1312.1 2372.5 Li Be B C N O F Ne 520.3 899.5 800.7 1086.5 1402.4 1314.0 1681.1 2080.8 Na Mg Al Si P S Cl Ar 495.9 737.8 577.6 786.5 1011.8 999.7 1251.2 1520.6 K Ca Ga Ge As Se Br Kr 418.9 589.9 578.6 761.2 946.5 940.7 1142.7 1350.8 Rb Sr In Sn Sb Te I Xe 402.9 549.2 558.2 708.4 833.8 869.0 1008.7 1170.3 Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188 First Ionization Energies (kJ/mol) s p H He 1312.1 2372.5 Li Be B C N O F Ne 520.3 899.5 800.7 1086.5 1402.4 1314.0 1681.1 2080.8 Na Mg Al Si P S Cl Ar 495.9 737.8 577.6 786.5 1011.8 999.7 1251.2 1520.6 K Ca Ga Ge As Se Br Kr 418.9 589.9 578.6 761.2 946.5 940.7 1142.7 1350.8 Rb Sr In Sn Sb Te I Xe 402.9 549.2 558.2 708.4 833.8 869.0 1008.7 1170.3 Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188 First Ionization Energies Metal Metalloid Nonmetal (kJ/mol) s p H He 1312.1 2372.5 Li Be B C N O F Ne 520.3 899.5 800.7 1086.5 1402.4 1314.0 1681.1 2080.8 Na Mg Al Si P S Cl Ar 495.9 737.8 577.6 786.5 1011.8 999.7 1251.2 1520.6 K Ca Ga Ge As Se Br Kr 418.9 589.9 578.6 761.2 946.5 940.7 1142.7 1350.8 Rb Sr In Sn Sb Te I Xe 402.9 549.2 558.2 708.4 833.8 869.0 1008.7 1170.3 Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188 5s 5p 4d 18 4s He 4p 3d 18 Ne Ar 3s 3p 8 First Ionization energy 2s Kr 2p 8 H 1s 2 NUCLEUS Li Na K Rb Atomic number First Ionization Energy Plot 5s 5p 4d 18 4s 4p 3d 18 3s 3p 8 2500 2s He 2p First ionization energy (kJ/mol) 8 Ne 2000 1s F 1500 N 1000 C Be O B 0 Na 5 Br P Mg Li Kr NUCLEUS Cl H 500 2 Ar 10 Zn S Si Al Fe Ni Ti Cr Ca Co Cu Mn Sc V As Ge Se Sr Ga K 15 Rb 20 Atomic number 25 30 35 40 Ionization Energies Energy electron gas liquid solid metal 1st ionization energy M(g) + I.E. gas phase M1+(g) + e1- ionization energy 2nd ionization energy M1+(g) + I.E. M2+(g) + e1- 3rd ionization energy M2+(g) + I.E. M3+(g) + e1- Ionization Energies (kJ/mol) 2nd 3rd 4th Element 1st H 1312.1 He 2372.5 5250.7 Li 520.3 7298.5 11815.6 Be 899.5 1752.2 14849.5 21007.6 B 800.7 2427.2 3660.0 25027.0 32828.3 C 1086.5 2352.8 4620.7 6223.0 37832.4 47279.4 Al 577.6 1816.7 2744.8 11577.5 14831.0 18377.9 Smoot, Price, Smith, Chemistry A Modern Course 1987, page 190 5th 6th Ionization Energies (kJ/mol) Element 1st 2nd 3rd 4th 5th 6th Na 498 4560 6910 9540 13,400 16,600 Mg 736 1445 7730 10,600 13,600 18,000 Al 577 1815 2740 11,600 15,000 18,310 Si 787 1575 3220 4350 16,100 19,800 P 1063 1890 2905 4950 6270 21,200 S 1000 2260 3375 4565 6950 8490 Cl 1255 2295 3850 5160 6560 9360 Ar 1519 2665 3945 5770 7320 8780 Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, page Shaded area on table denotes core electrons. Ionization Energies (kJ/mol) Element 1st 2nd 3rd 4th 5th 6th Na 498 4560 6910 9540 13,400 16,600 Mg 736 1445 7730 10,600 13,600 18,000 Al 577 1815 2740 11,600 15,000 18,310 Si 787 1575 3220 4350 16,100 19,800 P 1063 1890 2905 4950 6270 21,200 S 1000 2260 3375 4565 6950 8490 Cl 1255 2295 3850 5160 6560 9360 Ar 1519 2665 3945 5770 7320 8780 Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, page Shaded area on table denotes core electrons. Multiple Ionization Energies Al1+ Al 1st Ionization energy 2nd Ionization energy Al2+ Al3+ 3rd Ionization energy The second, third, and fourth ionization energies of aluminum are higher than the first because the inner electrons are more tightly held by the nucleus. Smoot, Price, Smith, Chemistry A Modern Course 1987, page 190 ? Factors Affecting Ionization Energy Nuclear Charge The larger the nuclear charge, the greater the ionization energy. Shielding effect The greater the shielding effect, the less the ionization energy. Radius The greater the distance between the nucleus and the outer electrons of an atom, the less the ionization energy. Sublevel An electron from a full or half-full sublevel requires additional energy to be removed. Smoot, Price, Smith, Chemistry A Modern Course 1987, page 189 Electron Affinity • The energy change associated with adding an electron to a gaseous atom. • Easiest to add to group 17. • Gets them to full energy level. • Increase from left to right atoms become smaller, with greater nuclear charge. • Decrease as we go down a group. Ionic Size • Cations form by losing electrons. • Cations are smaller that the atom they come from. • Metals form cations. • Cations of representative elements have noble gas configuration. Ionic size • Anions form by gaining electrons. • Anions are bigger that the atom they come from. • Nonmetals form anions. • Anions of representative elements have noble gas configuration. Formation of Cation sodium atom Na sodium ion Na+ ee- e- e- e- e- ee- e- 11p+ ee- loss of one valence electron e- e- 11p+ e- e- ee- e- e- ee- Formation of Anion chlorine atom Cl e- egain of one valence electron ee- e- e- chloride ion Cl1e- eee- e- e- e- e- ee- e- 17p+ 17p+ e- e- e- e- ee- e- e- e- e- e- ee- e- eeee- e- Formation of Ionic Bond chloride ion Cl1- sodium ion Na+ e- e- ee- e- e- e- e- e- ee- e- 11p+ e- e- e- e- e- e- 17p+ e- ee- e- e- e- ee- e- e- Nuclear charge increases Shielding increases Atomic radius increases Ionic size increases Ionization energy decreases Electronegativity decreases Summary of Periodic Trends Shielding is constant Atomic radius decreases Ionization energy increases Electronegativity increases Nuclear charge increases 1A 0 2A Ionic size (cations) decreases 3A 4A 5A 6A 7A Ionic size (anions) decreases Modern Atomic Structure Sublevel designation n=4 4s 4p n=3 n=2 3s 4d 3p 2s An orbital for a hydrogen atom. The intensity of the dots shows that the electron spends more time closer to the nucleus. 4f 3d 2p 1s n=1 The first four principal energy levels in the hydrogen atom. Each level is assigned a principal quantum number n. Hein, Arena, Foundations of College Chemistry, 2000, page 202 The types of orbitals in each of the first four principal energy levels. Resources - Periodic Table Objectives Worksheet - vocabulary Activity - aliens cards: A B key Activity - coloring periodic table Worksheet - periodic table paragraph Worksheet - ionization energies Lab - periodic trends database Project - element brochure example timeline Worksheet - periodic table textbook questions BINGO - element's symbols study sheet Outline (general) Binary Compounds Binary compounds that contain a metal of fixed oxidation number (group 1, group 2, Al, Zn, Ag, etc.), and a non-metal. To name these compounds, give the name of metal followed by the name of the non-metal, with the ending replaced by the suffix –ide. Examples: NaCl sodium chloride (Na1+ Cl1-) CaS calcium sulfide (Ca2+ AlI3 aluminum iodide (Al3+ 3 I1-) S2-) Cations and Anions Common Simple Cations and Anions Cation H 1+ Li 1+ Na 1+ K 1+ Cs 1+ Be 2+ Mg 2+ Al 3+ Ag 1+ Name hydrogen lithium sodium potassium cesium beryllium magnesium aluminum silver Anion H 1F 1Cl 1Br 1I 1O 2S 2- Name* hydride fluoride chloride bromide iodide oxide sulfide *The root is given in color. Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 86 Criss-Cross Rule Aluminum Chloride Example: Aluminum Chloride Step 1: write out name with space Step 2: Al 3+ Cl 1- write symbols & charge of elements Step 3: Al 1 Cl 3 criss-cross charges as subsrcipts Step 4: combine as formula unit (“1” is never shown) AlCl 3 Criss-Cross Rule Example: Aluminum Chloride Step 1: Aluminum Chloride Step 2: Al3+ Cl1- Step 3: Al 1 Cl 3 Step 4: AlCl 3 Criss-Cross Rule Example: Aluminum Oxide Step 1: Aluminum Oxide Step 2: Al3+ O2- Step 3: Al 2 O3 Step 4: Al2O3 Criss-Cross Rule Example: Magnesium Oxide Step 1: Magnesium Step 2: Mg2+ O2- Step 3: Mg 2 O2 Step 4: Step 5: Mg2O2 MgO Oxide Naming Binary Compounds Formula Name BaO barium oxide ____________________ NaBr 2 ________________ sodium bromide 1 3 MgI2 magnesium iodide ____________________ 4 KCl potassium chloride ____________________ SrF2 5 ________________ strontium fluoride CsF 6 ________________ cesium fluoride K1+ e- e- potassium atom 1BrBr bromine atom K Br e- bromine atom potassium atom K1+ bromide ion potassium potassium ion bromide potassium ion Br1- bromide ion KBr Br1- K1+ Mg2+ O2Br1- magnesium bromide MgBr2 K1+ potassium oxide K2O K1+ Br1- Al3+ N3PO43Pb4+ K1+ O2K1+ ? Ca2+ S2- Br1- OH1- Mg2+ Cu2+ Br1- NH41+ NO31- OH1- Chemical Bonding Activity Na1+ OH1- N3- Pb4+ Al3+ N3N3- M1+ (metal) (metal) M2+ (metal) M1+ (metal) N3- Pb4+ N2(nonmetal) Pb4+ N3- Ca2+ OH1Mg2+ ? Pb4+ N3- Pb3N4 OH1- lead (IV) nitride or plumbic nitride Pb4+ N3- Key http://www.unit5.org/christjs/4bondingact.doc 4. 1. 5. N3- K1+ Br1- Pb4+ N3- Al3+ KBr N3- 2. K1+ AlN O2K1+ 6. OH1OH1- Br1- Cu(OH)2 Mg2+ Br1MgBr2 N3- Cu2+ K2O 3. Pb4+ 7. NH41+ Pb4+ N3- NO31- NH4NO3 Pb3N4 Key 8. 9. 10. NH41+ Ca2+ O2PO4 NH41+ 3- PO43- Al3+ NH41+ Ca2+ O2(NH4)3PO4 PO43Ca2+ Ca3(PO4)2 11. Al3+ Fe2+ O2- O2- FeO Al2O3 13. 14. Key S2- Pb2+ 12. O2- S2- Pb4+ PbS Fe3+ S215. O2- Cu2+ O2- S2- CuO Fe3+ O2- Pb4+ 16. Cu1+ O2- S2Cu1+ Fe2O3 Pb PbS 2S 24 3 Cu2O Binary Compounds Containing a Metal of Variable Oxidation Number To name these compounds, give the name of the metal (Type II cations) followed by Roman numerals in parentheses to indicate the oxidation number of the metal, followed by the name of the nonmetal, with its ending replaced by the suffix –ide. Examples Stock System Traditional (OLD) System FeCl2 FeCl3 Iron (II) chloride Iron (III) chloride Ferrous chloride Ferric chloride SnO SnO2 Tin (II) oxide Tin (IV) oxide Stannous oxide Stannic oxide (“ic” ending = higher oxidation state; “ous” is lower oxidation state) Type II Cations Common Type II Cations Ion Stock System Fe 3+ Fe 2+ Cu 2+ Cu 1+ Co 3+ Co 2+ Sn 4+ Sn 2+ Pb 4+ Pb 2+ Hg 2+ Hg2 2+ iron (III) iron (II) copper (II) copper (I) cobalt (III) cobalt (II) tin (IV) tin (II) lead (IV) lead (II) mercury (II) mercury (I) Traditional System ferric ferrous cupric cuprous cobaltic cobaltous stannic stannous plumbic plumbous mercuric mercurous *Mercury (I) ions are always bound together in pairs to form Hg2 2+ Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 90 Naming Binary Compounds Formula Name 1 Hg2O mercury (I) oxide ____________________ 2 HgO mercury (II) oxide ____________________ CuF2 3 ________________ copper (II) fluoride Cu2S 4 ________________ copper (I) sulfide 5 Cr2O3 PbO2 6 ________________ chromium (III) oxide ____________________ lead (IV) oxide Binary Compounds Containing Two Nonmetals To name these compounds, give the name of the less electronegative element first with the Greek prefix indicating the number of atoms of that element present, followed by the name of the more electronegative nonmetal with the Greek prefix indicating the number of atoms of that element present and with its ending replaced by the suffix –ide. Prefixes you should know: Mono Di Tri Tetra Penta Hexa Hepta Octa Nona Deca 1 2 3 4 5 6 7 8 9 10 Binary Compounds Containing Two Nonmetals (Type III Compounds) As2S3 1. ________________ diarsenic trisulfide SO2 2. ________________ sulfur dioxide P2O5 diphosphorus pentoxide ____________________ CO2 4. ________________ carbon dioxide 3. 5. N2O5 dinitrogen pentoxide ____________________ 6. H2O dihydrogen monoxide ____________________ Binary Molecular Compounds N2O N2O3 N2O5 dinitrogen monoxide dinitrogen trioxide dinitrogen pentoxide ICl ICl3 iodine monochloride iodine trichloride SO2 SO3 sulfur dioxide sulfur trioxide Ternary Compounds Ternary compounds are those containing three different elements. (NaNO3, NH4Cl, etc.). The naming of ternary compounds involves the memorization of several positive and negative polyatomic ions, (two or more atoms per ion), and adding these names to the element with which they combine. i.e., Sodium ion, Na1+ added to the nitrate ion, NO31-, to give the compound, NaNO3, sodium nitrate. Binary rules for indicating the oxidation number of metals and for indicating the numbers of atoms present are followed. The polyatomic ions that should be learned are listed in a separate handout. Ternary Compounds NaNO2 sodium nitrite KClO3 potassium chlorate Ca3(PO4)2 calcium phosphate Fe(OH)3 iron (III) hydroxide NaHCO3 sodium bicarbonate „sodium hydrogen carbonate‟ Calcium hydroxide ide Ca2+ OH1- CaOH2 Ca - O H H vs. Ca(OH)2 HO - Ca - OH Common Polyatomic Ions Names of Common Polyatomic Ions Ion Name Ion Name NH4 1+ NO2 1NO3 1SO3 2SO4 2HSO4 1- ammonium nitrite nitrate sulfite sulfate hydrogen sulfate (“bisulfate” is a widely used common name) hydroxide cyanide phosphate hydrogen phosphate dihydrogen phosphate CO3 2HCO3 1- carbonate hydrogen carbonate (“bicarbonate” is a widely used common name) hypochlorite chlorite chlorate perchlorate acetate permanganate dichromate chromate peroxide OH 1CN 1PO4 3HPO4 2H2PO4 1- Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 100 ClO 1ClO2 1ClO3 1ClO4 1C2H3O2 2MnO4 1Cr2O7 2CrO4 2O2 2- Print Version Ternary Compounds Ca3(PO4) 2 1. ________________ calcium phosphate (NH4)2CO3 2. ________________ ammonium carbonate Al2(SO4)3 3. ________________ aluminum sulfate 4. Na2SO4 sodium sulfate ____________________ 5. LiCN lithium cyanide ____________________ 6. Ba(ClO3)2 Cu(OH)2 7. ________________ barium chlorate ____________________ copper (II) hydroxide Magnesium Phosphate Step 1: Magnesium Step 2: Mg2+ PO43- Step 3: Mg 3 (PO4) 2 Step 4: Phosphate Mg3(PO4)2 Phosphate (PO PO43)31P 4O 5+ = 335+ @ 2- = 8113@ ? Fluorine and oxygen are highly electronegative and will attract electrons very strongly. Generally, phosphorus will be 3- oxidation state - however, when combining with oxygen, phosphorus will lose five electrons and take on a 5+ oxidation charge. Polyatomic Ions - Memorize Eight “-ATE‟s” PO43SO4 …………… 2- …………… CO32ClO3 NO3 ………….. 1- ………….. 1- ………..…. phosphate phosphATE Exceptions: sulfate sulfATE carbonate carbonATE chlorate chlorATE nitrate nitrATE NH41+ …………… ammonium OH1- …………… hydroxide CN1- ………….. cyanide Polyatomic Ion: a group of atoms that stay together and have a single, overall charge. BrO41- Perbromate ion CO42ClO41IO41- NO41PO53SO521 more oxygen BrO31- BrO1- Bromate ion BrO21- Bromite ion CO32- CO22- CO2- ClO31- ClO21- ClO1- IO31- IO21- IO1- NO31- NO21- NO1- PO43- PO33- PO23- SO42- SO32- SO22- “normal” 1 less oxygen Carbonate ion Chlorate ion Iodate ion Nitrate ion Phosphate ion Sulfate ion Hypobromite ion 2 less oxygen Polyatomic Ion: a group of atoms that stay together and have a single, overall charge. BrO41- Perbromate ion CO42ClO41IO41- NO41PO53SO521 more oxygen BrO31- BrO1- Bromate ion BrO21- Bromite ion CO32- CO22- CO2- ClO31- ClO21- ClO1- IO31- IO21- IO1- NO31- NO21- NO1- PO43- PO33- PO23- SO42- SO32- SO22- “normal” 1 less oxygen Carbonate ion Chlorate ion Iodate ion Nitrate ion Phosphate ion Sulfate ion Hypobromite ion 2 less oxygen variable Ir2+,3+,4+,6+ Ir F 2(Cr 3 2O 7) 3 iridium (III) dichromate fluoride Ca S (OH)2 calcium hydroxide sulfide Ti S (CrO 2 4) 2 titanium (IV) chromate sulfide variable Ti3+,4+ Pt Cl (CH 2 3COO)2 platinum (II) acetate chloride variable Pt2+,4+ BaBr (BrO 2 3) 2 barium bromate bromide fixed Ba2+ Sr 3P SO 2 4 strontium sulfate phosphide fixed Sr2+ KF CN potassium cyanide fluoride fixed K1+ Zn I(NO 2 2) 2 zinc nitrite iodide fixed Zn2+ Mn Cl (ClO 4 3) 4 manganese (IV) chlorate chloride variable Mn2,3,4,6,7+ Au PO 2O34 gold (III) phosphate oxide Na NO 3P 3 sodium nitrate phosphide fixed Ca2+ variable Au1+,3+ fixed Na1+ variable Ir2+,3+,4+,6+ Ir F3 iridium (III) fluoride Ca S calcium sulfide Ti S2 titanium (IV) sulfide variable Ti3+,4+ Pt Cl2 platinum (II) chloride variable Pt2+,4+ BaBr2 barium bromide fixed Ba2+ Sr 3P2 strontium phosphide fixed Sr2+ KF potassium fluoride fixed K1+ Zn I2 zinc iodide fixed Zn2+ Mn Cl4 manganese (IV) chloride variable Mn2,3,4,6,7+ Au 2O3 gold (III) oxide Na 3P sodium phosphide fixed Ca2+ variable Au1+,3+ fixed Na1+ variable Ir2+,3+,4+,6+ Ir 2(Cr2O7)3 iridium (III) dichromate Ca (OH)2 calcium hydroxide Ti (CrO4)2 titanium (IV) chromate variable Ti3+,4+ Pt (CH3COO)2 platinum (II) acetate variable Pt2+,4+ Ba(BrO3)2 barium bromate fixed Ba2+ Sr 3SO4 strontium sulfate fixed Sr2+ KCN potassium cyanide fixed K1+ Zn (NO2)2 zinc nitrite fixed Zn2+ Mn (ClO3)4 manganese (IV) chlorate variable Mn2,3,4,6,7+ Au PO4 gold (III) phosphate Na NO3 sodium nitrate fixed Ca2+ variable Au1+,3+ fixed Na1+ Write the compound formed by the following ions: 1) Al3+ S22) Mg2+ PO43- When a formula is given…write the proper name. When a name is given…write the proper formula. 3) BaO 4) lithium bromide 5) Ni2S3 6) triphosphorus heptoxide 7) N2O5 8) molybdenum (VI) nitride Write the total number of atoms that make up each compound. 9) trinitrotoluene (TNT)… CH3C6H2(NO2)3 10) phosphoric acid H3PO4 Extra credit: What is the formula for plumbic iodide? (Hint: lead is Pb2+ or Pb4+) Write the compound formed by the following ions: 1) Al3+ S22) Mg2+ PO43- When a formula is given…write the proper name. When a name is given…write the proper formula. 3) BaO 4) lithium bromide 5) Ni2S3 POP QUIZ 6) triphosphorus heptoxide 7) N2O5 8) molybdenum (VI) nitride Write the total number of atoms that make up each compound. 9) trinitrotoluene (TNT)… CH3C6H2(NO2)3 10) phosphoric acid H3PO4 Extra credit: What is the formula for plumbic iodide? (Hint: lead is Pb2+ or Pb4+) Answer Key Write the compound formed by the following ions: 1) Al3+ S22) Mg2+ Al2S3 Mg3(PO4)2 PO43- When a formula is given…write the proper name. When a name is given…write the proper formula. 3) BaO barium oxide LiBr 4) lithium bromide nickel (III) sulfide 5) Ni2S3 P3O7 6) triphosphorus heptoxide 7) N2O5 dinitrogen pentoxide 8) molybdenum (VI) nitride MoN2 Write the total number of atoms that make up each compound. 9) trinitrotoluene (TNT)… CH3C6H2(NO2)3 10) phosphoric acid H3PO4 21 8 Extra credit: What is the formula for plumbic iodide? (Hint: lead is Pb2+ or Pb4+) PbI4 Binary Hydrogen Compounds of Nonmetals When Dissolved in Water (These compounds are commonly called acids.) The prefix hydro- is used to represent hydrogen, followed by the name of the nonmetal with its ending replaced by the suffix –ic and the word Acid added. Examples: *HCl Hydrochloric acid HBr Hydrobromic acid *The name of this compound would be hydrogen chloride if it was NOT dissolved in water. Naming Ternary Compounds from Oxyacids The following table lists the most common families of oxy acids. one more oxygen atom HClO4 perchloric acid most “common” HClO3 chloric acid H2SO4 sulfuric acid H3PO4 phosphoric acid HNO3 nitric acid one less oxygen HClO2 chlorous acid H2SO3 sulfurous acid H3PO3 phosphorous acid HNO2 nitrous acid two less oxygen HClO hypochlorous acid H3PO2 hypophosphorous acid (HNO)2 hyponitrous acid Suffixes have meaning “-ide” binary compound sodium chloride (NaCl) “-ite” or “-ate” sulfite (SO32-) sulfate (SO42-) “-ol” polyatomic compound “-ate” means one more oxygen than “-ite” alcohol methyl alcohol (methanol) “-ose” sugar sucrose “-ase” sucrase enzyme Empirical Formula Quantitative analysis shows that a compound contains 32.38% sodium, 22.65% sulfur, and 44.99% oxygen. sodium sulfate Find the empirical formula of this compound. 32.38% Na 32.38 g Na 1 mol Na 23 g Na = 1.408 mol Na / 0.708 mol = 2 Na 22.65% S 22.65 g S 1mol S 32 g S = 0.708 mol S / 0.708 mol =1S 44.99% O 44.99 g O 1mol O 16 g O = 2.812 mol O / 0.708 mol =4O Step 1) % g Step 2) g mol Step 3) mol mol Na2SO4 Empirical Formula A sample weighing 250.0 g is analyzed and found to contain the following: 27.38 g 27.38% 1.19% 1.19 g 14.29% 14.29 g 57.14% 57.14 g Na sodium H hydrogen C carbon O oxygen Assume sample is 100 g. Determine the empirical formula of this compound. Step 1) convert % gram Step 2) gram moles x mol Na 27.38 g Na 1mol Na 23 g Na x mol H 1.19 g H 1mol H 1g H x mol C 14.29 g C 1mol C 12 g C x mol O 57.14 g O 1mol O 16 g O Step 3) mol / mol 1.1904 mol Na / 1.19 mol = 1 Na 1.19 mol H / 1.19 mol = 1 H 1.1908 mol C / 1.19 mol = 1 C 3.5712 mol O / 1.19 mol = 3 O NaHCO3 Empirical & Molecular Formula (contains only hydrogen + carbon) (~17% hydrogen) A 175 g hydrocarbon sample is analyzed and found to contain ~83% carbon. The molar mass of the sample is determined to be 58 g/mol. Determine the empirical and molecular formula for this sample. Determine the empirical formula of this compound. Step 1) convert % gram Assume sample is 100 g. Then, 83 g carbon and 17 g hydrogen. MMempirical = 29 g/mol Step 2) gram moles x mol C 83 g C 1mol C 12 g C x mol H 17 g H 1mol H 1g H 2 C @ 12 g = 24 g 5H@ 1g = 5g 29 g 6.917 mol C / 6.917 mol = 1 C 17 mol H / 6.917 mol = 2.5 H (2.4577 H) CH2.5 C2H5 MMmolecular = 58 g/mol Step 3) mol / mol 58/29 = 2 Therefore 2(C2H5) = C4H10 butane Find the molar mass and percentage composition of zinc acetate Zn2+ CH3COO1acetate = CH3COO1- Zn(CH3COO)2 1 Zn @ 65.4 g/mol = 65.4 g / 183.4 g x 100% = 35.6 % Zn 4 C @ 12 g/mol 6 H @ 1 g/mol = 48 g = 6g 4 O @ 16 g/mol = 64 g Zn(CH3COO)2 183.4 g / 183.4 g x 100% = 26.2 % C / 183.4 g x 100% = 3.3 % H / 183.4 g x 100% = 34.9 % O A compound is found to be 45.5% Y and 54.5% Cl. Its molar mass (molecular mass) is 590 g. Assume a 100 g sample size a) Find its empirical formula 45.5 g Y 1 mol Y 88.9 g Y = 0.5118 mol Y / 0.5118 mol = 1 Y YCl3 54.5 g Cl 1 mol Cl 35.5 g Cl = 1.535 mol Cl / 0.5118 mol = 3 Cl 1 Y @ 88.9 g/mol = 88.9g 3 Cl @ 35.5 g/mol = 106.5 g b) Find its molecular formula 590 / 195.4 = 3 3 (YCl3) YCl3 Y3Cl9 195.4 g 6.02x1023 Molar Mass Atomic Mass vs. 2g H2 = _____ H2 = _______ 2 amu 18 g H2O = _____ H2O = ________ 18 amu 120 g MgSO4 = _____ MgSO4 = ________ 120 amu g (NH4)3PO4 = 149 _____ (NH4)3PO4 = ________ 149 amu Percentage Composition (by mass) % = part x 100 % whole Empirical vs. (lowest ratio) Molecular Formula Empirical Formula % g g mol mol mol Interpretation of a Chemical Formula O O S O O H H Sulfuric Acid H2SO4 Two atoms of hydrogen One atom of sulfur Four atoms of oxygen Chemical Formulas C8H18 Subscript indicates that there are 8 carbon atoms in a molecule of octane. Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 203 Subscript indicates that there are 18 hydrogen atoms In a molecule of octane. Stock System of Nomenclature CuCl2 Name of cation + Roman numeral indicating charge copper (II) Name of anion chloride Chemical Formulas Al2(SO4)3 Subscript 2 refers to 2 aluminum atoms. Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 204 Subscript 4 refers to 4 oxygen atoms in sulfate ion. Subscript 3 refers to everything inside parentheses. Here there are 3 sulfate ions, with a total of 3 sulfur atoms and 12 oxygen atoms. Naming Binary Ionic Compounds Al2O3 Name of cation Name of anion aluminum oxide Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 207 The OLD System of Nomenclature CuCl2 Name of cation + -ic higher oxidation # Name of anion -ous lower oxidation # Cupric Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 208 chloride Review TWO Elements Metal (fixed) + Non-metal binary -ide NaCl Group 1, Group 2, Ag, Zn, Al sodium chloride Metal (variable) + Non-metal Transition Elements STOCK system (Roman Numeral) CrCl2 OLD system chromium (II) chloride Cr2+ Cl1[-ic (higher) & -ous (lower)] Cu1+ or Cu2+ CuCl2 cupric chloride Sn stannum Pb plumbum Cu cuprum Au aurum Fe ferrum Three or more Elements Ternary Compounds Polyatomic Ions [-ate (one more O) & -ite (one less O)] LiNO3 LiNO2 Li3N lithium nitrate lithium nitrite lithium nitride (binary compound) Polyatomic Ions 1 more oxygen per____ate ClO41NO41CO42SO52PO53- perchlorate pernitrate percarbonate persulfate perphosphate [-ate (one more O) & -ite (one less O)] 1 less oxygen _____ite Memorize NORMAL _____ate chlorate nitrate carbonate sulfate phosphate ClO31NO31CO32SO42PO43- chlorite nitrite carbonite sulfite phosphite 2 less oxygen hypo_____ite ClO21NO21CO22SO32PO33- hypochlorite hyponitrite hypocarbonite hyposulfite hypophosphite ClO1NO1CO2SO22PO23- ammonium, cyanide, hydroxide NH41+ CN1- OH1- How many atoms in a formula unit of ammonium hypophosphite? 18 3 NH41+ PO23(NH4)3PO2 (Greek prefixes)……DO NOT REDUCE! Nonmetal & Nonmetal Mono Di Tri Tetra Penta Hexa Hepta Octa Nona Deca 1 2 3 4 5 6 7 8 9 10 Resources - Nomenclature Objectives Worksheet - binary cmpds: single charge cation Worksheet - ions in chemical formulas Worksheet - ionic cmpds: polyatomic ions w multiple-charge cation Worksheet - ionic formulas (binary, polyatomic, transition) Worksheet - empirical and molecular Worksheet - traditional system of nomenclature Worksheet - covalent binary cmpds: non-metal - non-metal Worksheet - ionic cmpds: polyatomic ions Worksheet - vocab (bonding) Worksheet - heat energy problems Activity - bonding pieces Worksheet - ionic binary cmpds: multiple charge cation Activity - molecular models Worksheet - errors in chemical formulas and nomenclature Worksheet - oxidation numbers and ionic cmpds activity - mole pattern Worksheet - names and formulas of cmpds Outline (general)