Here's how to determine the number of atoms in K₂CrO₄ (potassium chromate):

* Identify the elements: The formula tells us the compound contains potassium (K), chromium (Cr), and oxygen (O).

* Count the subscripts:

* There are 2 potassium atoms (K₂).

* There is 1 chromium atom (Cr).

* There are 4 oxygen atoms (O₄).

* Total atoms: 2 + 1 + 4 = 7 atoms

Therefore, there are 7 atoms in one molecule of K₂CrO₄.