1. Chemical Formula Guide
I need to:
Write a formula
A metal and a polyatomic ion
And I have:
So it is Ionic
A metal and a nonmetal
2 nonmetals
And I will:
Write the symbols for the ions of each part. (Roman numerals are + charges)
Adjust the quantity of each ion until the charges add up to zero
Write the symbol for the metal first
Write the number of atoms of that element as a subscript after the symbol
Write the symbol for the polyatomic anion last
If you need more than one of the polyatomic anion, put parentheses around it and write the subscript outside the parentheses
There are NO CHARGES in chemical formulas
Example: Calcium nitrate = Ca+2 and NO3-1
I need 1 Ca+2 and 2 NO3-1 to add up to zero
Ca(NO3)2
So it is Ionic
So it is Covalent
And I will:
Write the symbols for the ions of both elements. (Roman numerals are + charges)
Adjust the quantity of each ion until the charges add up to zero
Write the symbol for the metal first
Write the number of atoms of that element as a subscript after the symbol
Write the symbol for the nonmetal last
There are NO CHARGES in chemical formulas
Example: Iron (III) oxide = Fe+3 and O-2
I need 2 Fe+2 and 3 O-2 to add up to zero
Fe2O3
And I will:
Write the symbol for the element in the lowest group first. (exceptions – hydrogen always comes after carbon, and halogens always come before oxygen)
Write the number of atoms of that element as a subscript after the symbol. (translate prefixes)
Write the symbol for the right-most element last
Example: Nitrogen dioxide = NO2

2. Chemical Formula Guide
I need to:
Name a compound
And I have:
2 nonmetals
A metal and a nonmetal
A metal and a polyatomic ion
So it is Ionic
So it is Covalent
So it is Ionic
And I will:
Name the first element first.
If there is a subscript after the symbol, use a numeric prefix to name it
Name the second element last and change the ending to –ide
If there is a subscript after the symbol, use a numeric prefix to name it
Example: NO2 is named Nitrogen dioxide
Prefixes: 1=mono, 2=di, 3=tri, 4=tetra, 5=penta, 6=hexa, 7=hepta, 8=octa, 9=nona, 10=deca
And I will:
Name the metal first
If it is a transition metal, write its charge as Roman Numerals after the name
Name the nonmetal last and change the ending to -ide
Example: Fe2O3 is named Iron (III) oxide because the iron atom has a +3 charge
THERE ARE NO PREFIXES IN IONIC COMPOUNDS
And I will:
Name the metal first
If it is a transition metal, write its charge as Roman Numerals after the name
Name the polyatomic ion last and do not change the name of it
Example: Cu(NO3)2 is named Copper (II) nitrate because the copper atom has a +2 charge
THERE ARE NO PREFIXES IN IONIC COMPOUNDS