Instructions for Making Ionic Compounds
Ionic compounds are composed of metals and nonmetals.
Ionic compounds form in certain ratios depending on their charges.
1) Put oxidation number in the yellow boxes.
Oxidation number are the charges that atoms naturally have when near other
atoms. Metals lose electrons and become positive (Cations); nonmetals gain electrons
and become negative (Anions).
See a Chart of the Oxidation Numbers here.
Memorize oxidation numbers with
this exercise.
2) Put number of atoms in the blue boxes until the total charge of
the compound is zero. You must put at least a "1" in each box.
Negative atoms attract positive atoms (opposites attract). If two oppositely
charged atoms combine and still have a charge, then it will be attracted to
another atom of the opposite charge. Example: Na (Sodium) has a charge of +1;
Oxygen has a charge of -2. So together NaO has a charge of -1 (1 -2 = -1) and
will attract one more Na atom making Na2O, which has a net charge
of zero (1+1-2 = 0).
3) Click on "Check Formula" to see if you are right.
4) Click on "New Formula" to try again.