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

MetalsLocation: Left side of Periodic TableProperties: Ductile – drawn into wires

Malleable – hammered into sheetsMetallic Luster – shineGood Conductors of Heat and Electricity

NonmetalsLocation: Right side of Periodic TableProperties: Brittle

Lack Luster – not shinyPoor Conductors of Heat and Electricity

Semi-metalsLocation: Along Stair-stepProperties: Have properties of metals and nonmetals also called METALLOIDS Si, Ge, As, Sb, Te, Po, At

METALS

Nonmetals

Semi-metals

Naming1. Ionic Compounds – Formed from a metal and a non-metalWhen 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 – ionnet charge on compound = 0

Na+1 + Cl-1 NaCl Loses Gains compound electron electron NO CHARGE

Cation – positive ion – metalAnion – negative ion - nonmetal

Ions Formed ±4+1

+2

varies

+3 -3 -2 -1

0

Rules for writing formulas for Ionic Compounds

Binary compound – compound formed by two elementsTertiary 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 second2. Determine the charge on the atoms of each element3. 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 Oxide Aluminum Sulfide Potassium Sulfate

Ammonium Phosphate

Na+1 O -2

Na2O

Al +3 S -2

Al2S3

K +1 SO4-2

K2SO4

NH4+1 PO4

-3

(NH4)3PO4

Naming Ionic CompoundsName the Cation first – Name of the metalthe anion is the name of the nonmetal altered by adding the suffix -ide to the root word

chlorine chloridefluorine fluoridesulfur sulfideoxygen oxidephosphorus phosphideetc…

Polyatomic name is not alteredSome 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) = Hg2

+2

Examples:

NaCl KNO3

MgBr2 CuO

Li2SO4 Cu2O

K3N SnS2

= 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 Compounds2. Molecular Compounds (molecules) – compounds made from two nonmetals

- electrons are shared by two atoms

Naming MolecularPrefixes: (MEMORIZE)Mono-1 tetra-4 hepta-7 deca-10di-2 penta-5 octa-8tri-3 hexa-6 non-9prefixes are used with both the first named and second named element. Exception:

mono- is not used on the first wordsecond word ends in –ideIf 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

N2O dihydrogen monoxide

Si8O5 tetrasulfur hexachloride

NH3 carbon monoxide

P3I10 carbon dioxide

= Dinitrogen monoxide

= Octasilicon pentoxide

= Nitrogen trihydride

= Triphosphorus deciodide

= H2O

= S4Cl6

= CO

= CO2

Writing molecular formulasTranslate prefixes

Examples:

Naming AcidsAcid - has one or more H+1 ions attached to an anion Second Word is AcidIf the anion doesn’t contain oxygen, the acid is named with the prefix hydro-

and the suffix –ic attached to the rootWhen 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:

HCl hydroiodic acid

HClO3 hydronitric acid

HClO4 nitric acid

HClO2 nitrous acid

HClO sulfuric acid

= Hydrochloric acid

= Chloric acid

= Perchloric acid

= Chlorous acid

= hypochlorous acid

= HI

= H3N

= HNO3

= HNO2

= H2SO4