* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chemistry Review ATOMS
Strengthening mechanisms of materials wikipedia , lookup
Transition state theory wikipedia , lookup
Chemical Corps wikipedia , lookup
Biochemistry wikipedia , lookup
Chemical industry wikipedia , lookup
Gas chromatography–mass spectrometry wikipedia , lookup
Metastable inner-shell molecular state wikipedia , lookup
Computational chemistry wikipedia , lookup
Livermorium wikipedia , lookup
Chemical reaction wikipedia , lookup
Physical organic chemistry wikipedia , lookup
Molecular orbital diagram wikipedia , lookup
Chemical potential wikipedia , lookup
Electrochemistry wikipedia , lookup
X-ray fluorescence wikipedia , lookup
X-ray photoelectron spectroscopy wikipedia , lookup
Nuclear binding energy wikipedia , lookup
Nuclear transmutation wikipedia , lookup
Abundance of the chemical elements wikipedia , lookup
Isotopic labeling wikipedia , lookup
Hypervalent molecule wikipedia , lookup
Resonance (chemistry) wikipedia , lookup
Atomic orbital wikipedia , lookup
Electronegativity wikipedia , lookup
Stoichiometry wikipedia , lookup
Rutherford backscattering spectrometry wikipedia , lookup
Metalloprotein wikipedia , lookup
Metallic bonding wikipedia , lookup
Chemical element wikipedia , lookup
Periodic table wikipedia , lookup
Chemical thermodynamics wikipedia , lookup
Molecular dynamics wikipedia , lookup
Extended periodic table wikipedia , lookup
History of chemistry wikipedia , lookup
Electron configuration wikipedia , lookup
Atomic nucleus wikipedia , lookup
Chemical bond wikipedia , lookup
Chemistry: A Volatile History wikipedia , lookup
IUPAC nomenclature of inorganic chemistry 2005 wikipedia , lookup
Chemistry Review ATOMS • Smallest unit of matter. – Atoms make up everything (that has mass and takes up space). Protons (+) • Determines the identity of the Element • Represents the Atomic # • Positively charged • Nucleus • Part of the atoms mass Neutrons – No charge • Neutral – No charge • Nucleus • Part of the atoms mass Electrons (-) • • • • Negatively charged smallest particles Outside nucleus Found in the electron cloud • Located in energy levels Electric Charge of the Atom • Overall charge of an atom is Neutral • The # of (+) protons = the # of (–) electrons – They cancel each other out – Remember: • Protons are positive • Electrons are negative • Neutrons are neutral (No charge) – They do not count Atomic Particle Size Nucleus • • • • Center of the atom Made up of Protons and Neutrons Makes up the atoms MASS Positively Charged! Electron Cloud • Area around the nucleus where electrons are found. • Negatively Charged Energy Levels • Levels within the electron cloud that hold a specific # of electrons. – 1st level - 2 electrons – 2nd level - up to 8 electrons Valence Electrons • Electrons on the outermost energy level of the atom. • Determine the atoms chemical properties, including reactivity. Atomic Number • Top # on the periodic table • # of protons in the atom – Atomic # = 2 – 2 protons Chemical Symbol • 1 or 2 letter abbreviation for an element name – 1st letter Capitalized – 2nd letter – always lowercase • Helium - He Atomic Mass • • • • Bottom # Mass of the atom Located in the nucleus Protons + Neutrons Determining the # of subatomic particles in atoms Use the following A=P=E M–A=N Atomic # = Protons = Electrons Mass – Atomic # = Neutrons Atom Models ELEMENTS • All the atoms that make up our universe • Identified by the atomic # (# of protons) Arrangement of the Periodic Table Elements are arranged by: 1. By increasing Atomic # and mass • • According to the # of protons the atom has. Increases from left to right in each period (row) 2. By metals, non-metals and metalloids • According to their physical properties 3. By groups • According to their valence electrons and chemical properties – Reactivity – How they react chemically in chemical reactions. 3 Main Types of Elements on the Periodic Table Metals • • • • • Make up most of the elements All solid except Mercury Has luster (shiny) Good conductors of heat and electricity Malleable – hammered or shaped into thin sheets • Ductile – stretched into wires Nonmetals • Usually gases or brittle solids • Poor conductors of heat and electricity – They are insulators • Right side of the periodic table • Only 17 nonmetals Metalloids • Called Semi-metals • Share properties of both metals and nonmetals • Located on the zig-zag line between the metals and nonmetals. Groups/Families • 18 Vertical Columns on the periodic table • Elements have the same # of valence electrons • Elements share similar chemical properties including reactivity Periods • 7 horizontal rows on the periodic table • Increase by atomic # and mass • Consist of elements with the same number of energy levels. Chemical Compounds • A compound is when 2 or more elements chemically combine. • The properties of a compound are often very different from the elements themselves. – Example: Water – H2O • Compound with 2 hydrogen atoms and 1 oxygen atom Chemical Formulas • Formulas that use chemical symbols and numbers to represent what makes up a substance. – NaCl – Sodium chloride (salt) – Na – Sodium, Cl - Chlorine – H2O – Dihydrogen monoxide (water) – H – Hydrogen, O - Oxygen – CO2 – Carbon dioxide – C – Carbon, O - Oxygen Subscripts • Numbers written below and to the right of a chemical symbol in a formula. H2O – 2 Hydrogen, 1 Oxygen • Tells how many atoms of an element are in each molecule. • Only used if more than one atom is present. H2SO4 How many atoms of each element are in this compound? • H = Hydrogen – 2 atoms • S = Sulfur – 1 atom • O = Oxygen – 4 atoms How many elements are there? How many total atoms? • 3 elements 7 atoms Coefficients • # placed in front of a chemical symbol or formula • Identifies the # of molecules of a substance – 2H2O = 2 molecules of H2O – 3FeO3 = 3 molecules of FeO3 Coefficients X Subscripts • To determine the number of atoms using coefficients you multiply the coefficient with the subscript. • 2H2O - 2 molecules of H2O = 4 Hydrogen atoms and 2 Oxygen atoms 2Fe2O3 • 2 Molecules of Fe2O3 = • 2 X 2 = 4 Fe (iron) atoms • 2 X 3 = 6 O (oxygen) atoms Using Parentheses • Multiply the subscript with each element in parentheses. • Al2(SO4)3 • Al = 2 atoms of Aluminum • S = 3 X 1 = 3 atoms of Sulfur • O = 4 X 3 = 12 atoms of Oxygen Chemical Reactions • Occurs when one or more substances change to produce one or more different substances. • Atoms are rearranged to form a totally new substance with properties that are completely different • Indicators of a chemical reaction – – – – Gas formation Solid formation – precipitate Energy change – light, heat, or sound Color change Chemical Equations • Uses chemical symbols and formulas to represent a chemical reaction. • 2H2 + O2 → Reactants Yield Sign 2H2O Products Chemical Equations • Reactants – starting materials in a chemical reaction. • Products – substances formed in a chemical reaction. Law of Conservation of Mass • The mass of atoms and molecules is neither created nor destroyed in chemical reactions. – The # of atoms for each element in the reactants must equal the # of atoms for each element in the products in a chemical reaction. – Chemical Equations must be balanced. Chemical Equations Must Be Balanced! • Law of Conservation of Mass • The # of atoms in the reactants must equal the # of atoms in the products for each element 2H2 + O2 → 2H2O • Is this equation balanced? Reactants H= O= → 4 2 Is this equation balanced? Yes! Products H=4 O=2