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DO NOW: Match the scientists with the description. 1. Came up the plum pudding model. A. Modern Scientists 2. Came up the word atom from ”atomos” B. Thompson 3. Discovered the positive nucleus and the atom is mostly empty space. C. Bohr 4. Discovered the electrons travel in energy level (orbitals) D. Democritus 5. Came up the idea of electron clouds instead of orbitals. E. Rutherford The Periodic Table A. Mendeleev Dmitri Mendeleev (1869, Russian) ◦ Organized elements by increasing atomic mass. ◦ Elements with similar properties were grouped together. ◦ There were some discrepancies. C. Johannesson A. Mendeleev Dmitri Mendeleev (1869, Russian) ◦ Predicted properties of undiscovered elements. C. Johannesson Henry Moseley (1913, British) ◦ Organized elements by increasing atomic number. ◦ Resolved discrepancies in Mendeleev’s arrangement. B. Moseley C. Johannesson II. Organization of the Elements A. Metallic Character Metals Nonmetals Metalloids C. Johannesson B. Blocks Main Group Elements Transition Metals Inner Transition Metals C. Johannesson Do Now: Classify the following as either a METAL, NON-METAL or METALLOID: a.Au b.Si c. Br d.An element that is brittle and conducts electricity e.An element that is malleable f. An element that has tendency to become an anion Periods and Families Periods: horizontal rows on the periodic table ◦ physical and chemical properties change somewhat regularly across a row. ◦ Elements closer to each other in the same period tend to be similar than those that are farther apart. Families: vertical rows of elements, aka groups ◦ Each group contains similar chemical properties Types of Elements METALS: Shiny Conductors of heat and electricity Most metals are malleable (can be pounded into thin sheets; a sugar cube sized chunk of gold can be pounded into a thin sheet which will cover a football field), Most metals are ductile (can be drawn out into a thin wire). Metals cont….. All are solids at room temp (except Mercury, which is a liquid) Metals tend to have low ionization energies, and typically lose electrons (i.e. are oxidized) when they undergo chemical reactions Alkali metals are always 1+ (lose the electron in s subshell) Alkaline earth metals are always 2+ (lose both electrons in s subshell) Compounds of metals with nonmetals tend to be ionic in nature. Types of Elements NON- METALS: Vary greatly in appearance Non-lustrous Poor conductors of heat and electricity The melting points of non-metals are generally lower than metals Seven non-metals exist under standard conditions as diatomic molecules: H2(g) N2(g) O2(g) F2(g) Cl2(g) Br2(l) I2(l) (volatile liquid - evaporates readily) Nonmetals, when reacting with metals, tend to gain electrons (typically attaining noble gas electron configuration) and become anions: Nonmetal + Metal -> Salt Compounds composed entirely of nonmetals are molecular substances (not ionic) Non-Metals cont…….. Types of Elements Metalloids: Elements may share properties of metals and non-metals. A stair-step line separates the metals from the nonmetals on the periodic table. Metalloids cont…… Properties: All metalloids are solids at room temperature. Less malleable than metals but not as brittle as nonmetals. Metalloids tend to be semiconductors of electricity. (intermediate between metals and nonmetals). Metalloids cont…… Properties: Metalloids are used in semiconducting materials found in computers, calculators, televisions and radios. Elements include: boron, silicon, germanium, antimony Noble Gases Noble Gases - the elements in Group 18 of the periodic table. They are considered nonmetals. These elements are generally unreactive. All are gases at room temperature. Examples: neon, argon, krypton, xenon (all used in lighting) and helium. ATOMIC STRUCTURE History – ancient Greeks Democritus – (460-370 B.C.) • Matter is composed of atoms – moving around in empty space • Atoms are solid homogeneous, indestructible and indivisible • Different size and shape • Size shape & movement determine the properties of matter Aristotle – ( 384 322 B.C.) • Empty space cannot exist • Matter is made of earth, fire air and water https://www.youtube.com/watch?v=t hnDxFdkzZs Daltons Atomic Theory • • • • • • • John Dalton (1766-1844) Matter is composed of extremely small particles called atoms Atoms are indivisible and indestructible Atoms of a given element are identical in size, mass and chemical properties Atoms of a specific elements are different from those of another element Different atoms combine in simple whole number ratios to form compounds In a chemical reaction, atoms are separated, combined and rearranged Conservation of mass - Remember – Law of Conservation of mass states that mass is conserved - It is not destroyed or created (Atoms separate, combine or rearrange – Dalton) What is an Atom? • The smallest particle of an element that retains the properties of an element consists of PROTONS • NEUTRONS • ELECTRONS • Do Now 1. What are the three types of subatomic particles? 2. What charge does each of them have? 3. Where is each one located? Proton Electron Neutron Atom New Partners! Parts of the Atom ProtonIn nucleus, positive charge and a mass of 1 amu NeutronIn nucleus, neutral charge and a mass of 1 amu ElectronOutside nucleus, negative charge and no mass Complete the chart Part of Atom Proton Neutron Electron Charge Mass How do Atoms Differ? • The number of Protons identifies it as an atom of a particular element • Atoms are Neutral so the number of Protons (P) Equals the number of Electron (E) or P = E How do Atoms differ cont… • Atomic Number = The number of Protons = The number of Electrons Mass Number is the Atomic Number (Protons) PLUS number of Neutrons (NOT on the Periodic Table!) Mass Number = P + N THINK – PAIR - SHARE 1. Identify the atomic numbers for the following elements. A. He B. Be C. Ti D. F E. O 2. How many protons and how many electrons does fluorine have? How do Atoms differ cont… Every neutral (uncharged) atoms contains an equal number of positively charged protons (+) and negatively charged (-) electrons. # of (+) protons = # of (-) electrons Positive-Negative attractions between the protons in one atoms the electrons in another atom hold atoms together in bonds. DO NOW: Element Name Atomic Number Atomic Mass Au # of Electron # of Neutrons 12 Na W # of Protons 184 197 ISOTOPES Isotopes - Atoms of the same element have same number of protons BUT different number of Neutron EX: Copper has two isotopes : Cu 29 protons & 34 Neutrons (Cu - 63) Cu 29 Protons & 36 Neutrons (Cu - 65) https://www.youtube.com/watch?v=GsJPxR6IfZI Isotopes Atoms of the same element with different mass numbers. Nuclear symbol: Mass # 12 6 Atomic # Hyphen notation: carbon-12 C Isotopes © Addison-Wesley Publishing Company, Inc. 5. ELECTRONS Lets Look at ELECTRONS • • • • Found orbiting outside of the nucleus Electrons found at different energy levels Outer most electrons are called Valence Electron Valence Electrons determine the chemical properties of an element Lewis Dot Structure Valence Electrons: outermost electrons Electron Configuration: Energy Level MAX. # of electrons 1st 2 2nd 8 3rd 8 4th 18 Determining approximate placement of electrons Energy Level MAX. # of electrons 1st 2nd 3rd 4th Chlorine (atomic #_____) # protons = _____ # electrons = _____ WORKSHEET Outermost energy level: _________ # of valence electrons: __________ DO NOW Energy Level MAX. # of electrons 1st 2nd 3rd 4th Oxygen (atomic #_____) # protons = _____ # electrons = _____ TAKE OUT YOUR HOMEWORK!!!!!!!!! Outermost energy level: _________ # of valence electrons: __________ Isotopes Atoms of the same element with different mass numbers. Nuclear symbol: Mass # 12 6 Atomic # Hyphen notation: carbon-12 C Lewis Dot Structure: Practice: Draw the Lewis Dot Diagrams for the following Atoms: Ca Li F Worksheet: Lewis Dot Diagrams Do Now: Draw the Lewis Dot Diagrams for the following Atoms: Ar K S Take out your homework. Do Now: How many protons, neutrons, and electrons do the following examples contain? Take out your homework. History – ancient Greeks Give handout of History of the atom Democritus – (460-370 B.C.) • Matter is composed of atoms – moving around in empty space • Atoms are solid homogeneous, indestructible and indivisible • Different size and shape • Size shape & movement determine the properties of matter Aristotle – ( 384 322 B.C.) • Empty space cannot exist • Matter is made of earth, fire air and water Daltons Atomic Theory • John Dalton (1766-1844) • • • Matter is composed of atoms Atoms are indivisible and indestructible Atoms of a given element are identical in size, mass and chemical properties Atoms of a specific elements are different from those of another element Different atoms combine in simple whole number ratios to form compounds In a chemical reaction, atoms are separated, combined and rearranged • • • J.J. Thomson Cathode Ray Experiment http://www.youtube.com/watch?v=XU8nMKkzbT8 Background Born in Manchester, England in December 1856 Studied physics and mathematics Won a nobel prize in 1906 Experiment Observations 1. An object placed between the cathode and the opposite end of the tube cast a shadow on the glass. 2. A paddle wheel placed on rails between the electrodes rolled along the rails from the cathode toward the anode. 3. Cathode rays were deflected by a magnetic field in the same manner as a wire carrying electric current, which was known to have a negative charge. 4. The rays were deflected away from a negatively charged object. Discovery of Electrons-1897 Experiments supported hypothesis that the particles that compose cathode rays are negatively charged Measured the ratio of cathode-ray particles to their mass—found it was always the same Concluded that all cathode rays are composed of identical negatively charged particles called electrons Experiments revealed the electron has a very large charge for its tiny mass Lord Rutherford of Nelson As flawlessly explained by: Adam, Jane, Justin, Jeremy, rob Rutherford - History Born 1871 in New Zealand In early work, discovered radioactive half-life Had an element named after himrutherfordium Became known as the father of nuclear physics Assistants - Geiger and Marsden bombarded a thin piece of gold foil with a narrow beam of alpha particles. Some of the particles were redirected by the gold foil back towards their source. Rutherford thus concluded that the force must be caused by a very densely packed bundle of matter with a positive charge, which he called the nucleus. Discovery of the Atomic Nucleus The Experiment Rutherford had discovered that the volume of the nucleus was very small compared to the total volume of the atom, suggesting that there was a lot of empty space. Unit 4 . IONS https://www.youtube.com/watch?v= 900dXBWgx3Y Ions and Ionic Compounds Recall: Molecules make up one kind of Molecular compound. Ions make up another kind of compound- called Ionic Compound 57 IONS cont…… • Ions are electrically charged atoms (or groups of atoms). • Ions are formed when neutral atoms gain or lose Valence electrons. List the number of protons, electrons, and neutrons in Do Now ◦ 1. What is an ion? ◦ 2. What is a cation? ◦ 3. What is an anion? ◦ 4. Is the following a cation, anion, or neutral atom? O2- SW 1. SWBAT identify cations and anions. 2. SWBAT calculate the number of protons, neutrons, and electrons in different ions. 3. SWBAT to predict the ion the atom will most likely form. Objectives Ions ◦ Recall: What charge do electrons carry? Negative ◦ When atoms gain negative electrons, they form negative ions. ◦ When atoms lose negative electrons, they form positive ions. 61 Ions For example, sodium (Na) is # 11 on the Periodic Table. It has 11 (+) protons and 11 (-) electrons. If it lost 1 (-) electron, it would have 11 (+) protons and 10 (-) electrons. It has one more proton than electrons, so it has a charge of +1. The symbol for a sodium ion is Na1+ or just Na+. (The 1 is understood.) 62 Ions ◦ For another example, chlorine (Cl) is # 17 on the Periodic Table. ◦ It has 17 (+) protons and 17 (-) electrons. ◦ If it gained 1 (-) electron, it would have 17 (+) protons and 18 (-) electrons. ◦ It has one less proton than electrons, so it has a charge of -1. ◦ The symbol for a chloride ion is Cl1- or just Cl-. (The 1 is understood.) 63 Think – Pair- Share ◦ Identify the number of protons and neutrons for the following examples. ◦ 1. Si2p= ______ n= __14____ e= ______ ◦ 2. Na+ p= ______ n= __12____ e= ______ ◦ 3. F◦ p= ______ n= __10____ e= ______ Do any of these atoms have complete valence shells? List the number of protons, electrons, and neutrons in Do Now ◦ 1. What charge do elements in group 2 get? ◦ 2. What charge do elements in group 16 get? ◦ 3. What charge do elements in group 18 get? ◦ 4. Cations tend to be metal or nonmetals??? ◦ 5. Anions tend to be metal or nonmetals??? List the number of protons, electrons, and neutrons in Do Now ◦ 1. What charge does Li get when it becomes an ion? ◦ 2. Is it a cation or anion? ◦ 3. What charge does O get when it becomes an ion? ◦ 4. Is it a cation or anion? SW BAT determine the formulas for ionic compounds SWBAT name different ionic compounds Objectives https://www.youtube.com/watch?v=zpaHPXVR8WU Ionic Compounds Oppositely charged ions connect together to form ionic compounds. For example, sodium ions (Na+) connect to chloride ions (Cl-) to make sodium chloride (NaCl), or table salt. 68 Sodium chloride consists of an equal number of positive and negative ions arranged in a 3dimensional network called a crystal. A scanning electron micrograph shows the cubic structure of NaCl crystals. 69 A space-filling model of Nacl provides information about how the individual sodium ions & chloride ions are arranged within the salt crystal. What else does this model suggest about the sodium and chloride ions or sodium chloride? 70 If an ionic compound dissolves in water, the individual ions would separate from each other and spread out throughout the water. To show that they were now in an aqueous solution, an (aq) would be added after the symbols for the ions. Na+(aq) Cl- (aq) 71 More about Ions Cation – positive ion Na+, Anion – negative ion Cl- Monoatomic ions (or monatomic) Na+, Cl-, Mg2+, O2-, Al3+, N3- Polyatomic ions NH4+, CO32-, SO42-, PO43- 72 Common Ions See text p. 40 for a list of common ions. 73 Formulas for Ionic Compounds 3 Rules for Writing Formulas for Ionic Compounds 1. Cation first, then anion 2. Correct formula will be neutral, with the fewest number of each ion needed to make the total electrical charge zero 3. No charges are shown in the formula. 74 Practice Problems NaCl ◦ One Na1+ and one Cl1- cancel each other out. +1 + -1 = 0 CaCl2 ◦ One Ca2+ needs two of the Cl1- to cancel it out. +2 + -1 + -1 = 0 Note: Negative monoatomic ions change their ending to “ide.” Examples above are sodium chloride and calcium chloride. Formulas Containing Polyatomic Ions Formulas for compounds containing polyatomic ions follow the same rules If a subscript is needed, it follows the entire polyatomic ion, which is enclosed in parentheses For example, the calcium ion has a +2 charge, and the nitrate ion has a 1 charge 76 Formulas Containing Polyatomic Ions For example, the calcium ion has a +2 charge (Ca2+), and the nitrate ion has a -1 charge (NO31+). Two nitrate ions are needed to balance out the charge on one calcium ion. The formula for calcium nitrate is: Ca(NO3)2. No charges are shown in the formula. Polyatomic ions do not change their endings. 77 Find trends on the periodic table Practice: Work Worksheet on writing ionic compounds List the number of protons, electrons, and neutrons in Do Now ◦ ◦ ◦ ◦ 1. What is an ion? 2. What is a polyatomic ion? Monoatomic ion? 3. What is an ionic compound? 4. What type of “bond” holds an ionic compound together? DO NOW: Write the formula and name the following ionic compounds 1. Ca2+ 2. PO433. CO324. Al3+ What does the word “ionic” mean? BrAg+ NH4+ NO3- Try THESE! Write the formula following ionic compounds 1. Lithium and Oxygen 2. Calcium and Hydroxide 3. Ammonium and Phosphate Naming Ionic Compounds https://www.youtube.com/watch?v=vfYnhnfdsD0 1. Name the cation, then the anion 2. Have the last few letters changed to –ide (monoatomic ions only) Ex. KF, potassium fluoride Ex. Ca(NO3)2, calcium nitrate Practice Worksheet Unit 1B.9 & B.10 Ion supplement TRY THIS… Write the formula and name the following ionic compounds 1. Ca2+ 2. PO433. CO324. Al3+ What does the word “ionic” mean? BrAg+ NH4+ NO3- Do Now Write the name for following ionic compounds 1. K2S 2. B2(SO3)3 3. NH4Cl Worksheet (Unit 1B.9 part 3) Practice: Study for quiz ◦ ◦ ◦ ◦ What are ions? Polyatomic ions? Monoatomic ions? How do you find the charge on a monoatomic ion? What is an ionic compound? Ionic bond? Writing formulas for ionic compounds. Where does the cation go? Anion? ◦ Writing names for ionic compounds.