Learning to Name and Write Formulas:

- Determining the type of compound you are working with.

- Applying the rules for naming or formula writing for that type of compound.

- Practicing until it becomes second nature.

How to Find the Ionic Charge for an Element

When you are working with ionic compounds (they are called ionic because they consist of ions) you'll often need to determine the ionic charge. This is especially the case when you are writing formulas based on the chemical name.

To find the ionic charge of an element you'll need to consult your Periodic Table. On the Periodic Table metals (found on the left of the table) will be positive. Non-metals (found on the right) will be negative. But you need to know the specific ionic charge elments.

The image below shows the general trend for ionic charge. This is often taught in high school chemistry.

Ionic Charges on Periodic Table (General Trend)

For a more specific description see the image below which highlights a few exceptions. Note that the elements that are in blue/purple have charges that vary or where ionic charge is not appropriate.

Periodic Table with Ionic Charges - Complete Version

Memorizing Polyatomic Ion