Final answer:
The compound K₂CrO₄ consists of two potassium ions (K+) and one chromate ion (CrO₄²-).
Step-by-step explanation:
The compound K₂CrO₄ consists of two potassium ions (K+) and one chromate ion (CrO₄²-). The potassium ion has a charge of +1, while the chromate ion has a charge of -2. Therefore, the polyatomic ion in the compound is the chromate ion, CrO₄²-, which carries a charge of -2.