Here's how to break it down:

* Sodium (Na): This is the cation (positively charged ion) in the compound.

* Phosphite (HPO₃²⁻): This is the anion (negatively charged ion) in the compound. It contains phosphorus (P) and oxygen (O) with a hydrogen (H) atom attached.

* Subscripts: The subscripts indicate the number of each atom in the compound.

The two sodium atoms balance the negative charge of the phosphite ion, making the compound electrically neutral.