Nomenclature

Chemical Formula – type of notation made with numbers and chemical symbols –indicates the composition of a compound –indicates the number of atoms in one molecule Molecule - Bonded collection of two or more atoms of the same element or different elements - monatomic molecule – one atom molecules - diatomic molecule – two atom molecules (seven) MEMORIZE Br, I, N, Cl, H, O, F

Metals Location: Left side of Periodic Table Properties: Ductile – drawn into wires Malleable – hammered into sheets Metallic Luster – shine Good Conductors of Heat and Electricity Nonmetals Location: Right side of Periodic Table Properties: Brittle Lack Luster – not shiny Poor Conductors of Heat and Electricity Semi-metals Location: Along Stair-step Properties: Have properties of metals and nonmetals also called METALLOIDS Si, Ge, As, Sb, Te, Po, At METALS Nonmetals Semi-metals

Naming 1. Ionic Compounds – Formed from a metal and a non-metal When a metallic element combines chemically with a non-metallic element to form an ionic compound one or more electrons are transferred from each atom of the metal to one or more atoms of the nonmetal charged atom – ion net charge on compound = 0 Na +1 + Cl -1  NaCl Loses Gainscompound electron electronNO CHARGE Cation – positive ion – metal Anion – negative ion - nonmetal Ions Formed ± varies

Rules for writing formulas for Ionic Compounds Binary compound – compound formed by two elements Tertiary compound - compound formed by more than two elements Polyatomic ion – groups of atoms of more than one element that carries a charge –bound tightly together –don’t break apart during a chemical reaction, function as a unit 1. Write the symbols – cation first, anion second 2. Determine the charge on the atoms of each element 3. Select subscripts that make the lowest ratio TOTAL POSITIVE CHARGE = TOTAL NEGATIVE CHARGE –When using subscripts with polyatomic ions, the formula for the ion is placed in parentheses and the subscript is placed outside the parenthesis Examples: Sodium OxideAluminum Sulfide Potassium Sulfate Ammonium Phosphate Na +1 O -2 Na 2 O Al +3 S -2 Al 2 S 3 K +1 SO 4 -2 K 2 SO 4 NH 4 +1 PO 4 -3 (NH 4 ) 3 PO 4

Naming Ionic Compounds Name the Cation first – Name of the metal the anion is the name of the nonmetal altered by adding the suffix -ide to the root word chlorine  chloride fluorine  fluoride sulfur  sulfide oxygen  oxide phosphorus  phosphide etc… Polyatomic name is not altered Some metals can form more than one kind of ion (Type II) Fe, Cu, Co, Sn, Pb, Hg … Stock System – name the metal followed by a roman numeral in parenthesis. The Roman numeral tells the charge. Exception: Mercury (I) = Hg 2 +2 Examples: NaClKNO 3 MgBr 2 CuO Li 2 SO 4 Cu 2 O K 3 NSnS 2 = sodium chloride = magnesium bromide = lithium sulfate = potassium nitride = potassium nitrate = copper (II) oxide = copper (I) oxide = tin (IV) sulfide I, II, III, IV, V, VI, …

Molecular Compounds 2. Molecular Compounds (molecules) – compounds made from two nonmetals - electrons are shared by two atoms Naming Molecular Prefixes: (MEMORIZE) Mono-1tetra-4hepta-7deca-10 di-2penta-5octa-8 tri-3hexa-6non-9 prefixes are used with both the first named and second named element. Exception: mono- is not used on the first word second word ends in –ide If a two syllable prefix ends in a vowel, the vowel is dropped before the prefix is attached to a word beginning with a vowel monooxide N 2 Odihydrogen monoxide Si 8 O 5 tetrasulfur hexachloride NH 3 carbon monoxide P 3 I 10 carbon dioxide = Dinitrogen monoxide = Octasilicon pentoxide = Nitrogen trihydride = Triphosphorus deciodide = H 2 O = S 4 Cl 6 = CO = CO 2 Writing molecular formulas Translate prefixes Examples:

Naming Acids Acid - has one or more H +1 ions attached to an anion Second Word is Acid If the anion doesn’t contain oxygen, the acid is named with the prefix hydro- and the suffix –ic attached to the root When the anion contains oxygen, the suffix –ic or -ous is added -ate becomes –ic -ite becomes –ous Writing formulas for acids Balance charges between H +1 and anion. Examples: HClhydroiodic acid HClO 3 hydronitric acid HClO 4 nitric acid HClO 2 nitrous acid HClOsulfuric acid = Hydrochloric acid = Chloric acid = Perchloric acid = Chlorous acid = hypochlorous acid = HI = H 3 N = HNO 3 = HNO 2 = H 2 SO 4