Here's why:

* Zinc sulfate: This refers to the salt formed by the zinc cation (Zn²⁺) and the sulfate anion (SO₄²⁻).

* Heptahydrate: This indicates that there are seven water molecules (H₂O) associated with each formula unit of zinc sulfate. The prefix "hepta-" means seven.

Therefore, the full name combines the name of the salt with the number of water molecules present.