Sadie Baker and Courtney Hall

What is an Ionic Compound? Ionic compounds are basically defined as being compounds where two or more ions are held next to each other by electrical attraction. One of the ions has a positive charge (called a "cation") and the other has a negative charge ("anion"). Cations are usually metal atoms and anions are either nonmetals or polyatomic ions (ions with more than one atom).

Naming Ionic Compounds Most ionic compounds have two word names. The first word in the name is the name of the cation, and the second word is the name of the anion. The best way to go about naming ionic compounds is to take a look at the formula and figure out the names of the cation and anion. When you've got that, just stick them together and you've got the name of the compound.

Cations So, how do we name cations? If the cation is a main group element, the name of the cation will just be the name of the element. If the cation is a transition metal, you need check out whether or not there is more than one possible charge for that element. For example, iron can have a charge of either +2 or +3. As a result, you need to specify whether the cation has a +2 or a +3 charge. When you've done this, just put the number after the name of the element in Roman numerals. For example, the Fe +3 ion has the name "iron (III)".

Anions How about anions? If the anion has only one atom, then the name of the anion is the same as the name of the element except the end of the element name is taken off and "-ide" is added to the end. If the anion has more than one atom, then we'd say that it's a "polyatomic ion", meaning that the anion has more than one atom.