1.1 – Nomenclature
Naming Compounds & Writing their Chemical Formulas
nomenclature = naming and determining formulas of compounds
oxidation state = the # of e- an atom can lose (usually a metal)
o same as combining capacity
o used only when referring to cations (“+” ions)
reduction state = the # of e- an atom can gain (usually a nonmetal)
o same as combining capacity
o used only when referring to anions (“ – ” ions)
A) Ionic Bonding
Binary  metal + non-metal
 only 2 elements  aka binary compound
o like a bicycle, which has 2 wheels
 e- are transferred (given or taken) to achieve a full outer shell
o metals give up their e- and become cations
o non-metals take e- and become anions
Writing Formulas: Cross & drop method
1. Write the symbol and ion charge of the metal 1st, then symbol &
ion charge of the non-metal 2nd
2. Switch the charges (cross over) and write as subscripts
3. Drop the + / - signs
4. Write the formula with subscripts in lowest terms
Practice: Write the chemical formulas for the following metals & non-metals.
a) Potassium + bromine = …………………………………………………………………….
b) Magnesium + iodine = ……………………………………………………………………..
c) Silver + phosphorus = ……………………………………………………………………..
d) Zinc + chlorine = ……………………………………………………………………………
Naming
1. Write name of metal 1st, non-metal 2nd
2. Change the ending of non-metal to “ide”
Practice: Name the following binary compounds.
a) LiCl = …………………………………………………..
b) Na2S = …………………………………………………
c) CaF2 = …………………………………………………
d) Al2O3 = ………………………………………………..
Multivalent  Elements with Multiple Ion Charges
 happens with many transition metals & metalloids
o when 1st element (the metal) has more than one ion
charge (combining capacity)
 2 ways to name these
i. IUPAC system (uses roman numerals) tells you which ion
charge to use:
o (I) = 1+
(II) = 2+
(III) = 3+
(IV) = 4+
ii. Stock (old school) system
o lower ion charge gets “ous” ending
o higher ion charge gets “ic” ending
 examples of elements that are multivalent:
Element
Fe
Cu
Hg
Sn
Pb
Charges
2+, 3+
1+, 2+
1+, 2+
2+, 4+
2+, 4+
Mn
2-4,6,7+
Ti
Mo
Au
Cr
Co
Ni
Sb
3+, 4+
2+, 3+
1+, 3+
2+, 3+
2+, 3+
2+, 3+
3+,5+
Stock System
ferrous / ferric
cuprous / cupric
mercurous / mercuric
stannous / stannic
plumbous / plumbic
IUPAC system
iron (II) / iron (III)
copper (I) / copper (II)
mercury (I) / mercury (II)
tin (II) / tin (IV)
lead (II) / lead (IV)
manganese (II), (III), (IV),
(VI), (VII)
titanium (III), (IV)
molybdenum (II), (III)
gold (I), (III)
chromium (II), (III)
cobalt (II), (III)
nickel (II), (III)
antimony (III), (V)
Writing Formulas  same as binary ionic bonding
1. Write the symbol and ion charge of the metal 1st, then symbol &
ion charge of the non-metal 2nd
2. Switch the charges (cross over) and write as subscripts
3. Drop the + / - signs
4. Write formula with subscripts in lowest terms.
Practice: Write the chemical formulas for the following multivalent ionic compounds.
a) Nickel (II) nitride = …………………………………………………………………….
b) Stannous fluoride = …………………………………………………………………..
c) Gold (III) oxide = ………………………………..…………………………………….
d) Plumbic sulfide = ………………………………………………………………………
Naming
1. Write name of metal 1st, non-metal 2nd
2. Add roman numeral to indicate ion charge used OR add ous/ic
ending (look at the subscript on the 2nd element for help)
3. Change the ending of non-metal to “ide”
Practice: Name the following multivalent ionic compounds.
a) CuCl2 = ……………………………………………………………………………………
b) TiBr4 = …………………………………………………………………………………….
c) HgF = ……………………………………………………………………………………..
d) Fe2O3 = …………………………………………………………………………………..
Polyatomic ions  metal + non-metal cluster
 non-metal clusters (mostly) involving oxygen
o “ate” or “ite” endings are non-metals bonded to oxygen
 same as ionic bonding, but non-metal part contains 2+ elements
 there are dozens, but 5 common ones that you’ll use are listed
below
Main Polyatomic Ion
Prefixes & Suffixes
Per…………ate 1 more oxygen
Carbonate
CO32-
Chlorate
ClO31-
…………ate
Nitrate
NO31-
………….ite
Phosphate
PO43-
Sulfate
SO42-
main ion
1 less oxygen
Hypo………..ite 2 less oxygen
Writing Formulas  same as ionic bonding
1. Write the symbol and ion charge of the metal 1st
2. Use chart above to find symbols & ion charge of the polyatomic
ion, then write it 2nd
3. Switch the charges (cross over) and write as subscripts
4. Drop the + / - signs
5. Write formula with subscripts in lowest terms.
Practice: Write the chemical formulas for the following polyatomic ionic compounds.
a) Lithium sulfate = …………………………………………………………………….
b) Sodium cyanide = ……………….………………………………………………..
c) Aluminum chlorate = …………………………………………………………………….
d) Beryllium nitrite = ……………………….………………………………………………
Naming
1. Write name of metal 1st
2. Look up polyatomic ion in chart, then write it 2nd
Practice: Name the following polyatomic compounds.
a) AgNO3 = …………………………………………………..
b) CaCO3 = ……………………………………………………
c) K3PO4 = …………………………………………………….
d) Mg(OH)2 = …………………………………………………..
Oxy-acids  polyatomic ions + H atom(s)
 instead of a metal, hydrogen is bonded to a polyatomic ion
o hydrogen can act like a metal
 all oxy-acids contain H and O atoms
 there are 5 main oxy-acids that end in “ic”, see below
o “ic” or “ous” indicates an acid
Main Oxy-acids
Carbonic acid
Chloric acid
Nitric acid
Phosphoric acid
Sulfuric acid
H2CO3
HClO3
HNO3
H3PO4
H2SO4
Oxy-acid Derivative Prefixes &
Suffixes
Per…………ic
1 more oxygen
…………ic
main acid
…………ous 1 less oxygen
Hypo……….ous 2 less oxygen
Writing Formulas  same as ionic bonding
1. Write the symbol and ion charge of hydrogen 1st
2. Use chart above to find symbols & ion charge of the polyatomic
ion, then write it 2nd
3. Switch the charges (cross over) and write as subscripts
4. Drop the + / - signs
5. Write formula with subscripts in lowest terms.
Practice: Write the chemical formulas for the following oxy-acids.
a) Sulfuric acid = …………………………………………………………………….
b) Nitric acid = ……………….………………………………………………..
c) Chlorous acid = …………………………………………………………………….
Naming
1. Use your chart to name the compound. Pay attention to the
subscript on the polyatomic to determine the ending (“ic”/“ous”)
Practice: Name the following oxy-acids.
a) H2CO3= …………………………………………………..
b) HCl = ……………………………………………………
c) H2PO5 = …………………………………………………….
B) Molecular (Covalent) Bonding
Molecular  non- metal + non-metal
 aka covalent bonding
 instead of giving up or taking e- to achieve a full outer shell,
pairs of e- are shared
Writing Formulas  Use prefix system
1. Write the symbol of the 1st non-metal, then the symbol of the 2nd
non-metal
2. Use prefixes on the elements to determine the # of atoms of each
element (if the 1st element doesn’t have a prefix, it has only 1
atom)
3. Write the # of atoms as subscripts.
Practice: Write the chemical formulas of the following molecular compounds.
a) Carbon dioxide = ………………………………………………………
b) Sulfur trioxide = ………………………………………………………..
c) Silicon monocarbide = ……………………………………………….
d) Diphosphorus trioxide = …………………………………………………..
Naming
1. Write the name of the 1st non-metal, then the 2nd. Leave a bit of
space between them
2. Change the ending of 2nd non-metal to “ide”
3. Use subscripts to determine the # of atoms of each element
o add prefixes to both elements to indicate the # of atoms
 except if 1st element has only 1 atom (then no prefix)
mono – 1
di – 2
tri – 3
tetra – 4
penta – 5
hexa – 6
Practice: Name the following molecular compounds.
a) CF4 = ……………………………………………………….
b) SO2 = ………………………………………………………
c) PBr3 = ……………………………………………………..
d) H2O = ……………………………………………………….
hepta – 7
octa – 8
Diatomic Molecules  non-metal “twins”
 non-metals who combine 2 (or more) of their atoms to form a
stable molecule
o prefix di = 2
 these elements are never found alone (like Siamese twins)
Mnemonics: Dr. H O F Br I N Cl
Practice: Write the chemical formulas for the following diatomic molecules.
a) Oxygen gas = …………………………….
b) Nitrogen gas = ……………………………
c) Hydrogen gas = ………………………….
d) Fluorine gas = ……………………………