The compound CaSO₄ ionizes into a calcium ion and a sulfate ion (SO₄). Calcium has two electrons in its outer shell. Upon ionization, what would you expect the charge on the sulfate ion to be?

• A. –4
• B. –1
• C. +1
• D. –2

Answer: (D)

Verified step by step guidance

1. Understand that when CaSO4 ionizes, it separates into a calcium ion (Ca^2+) and a sulfate ion (SO4^2-).
2. Recognize that calcium (Ca) typically loses two electrons to achieve a stable electron configuration, resulting in a Ca^2+ ion.
3. Since the compound CaSO4 is neutral overall, the charges of the ions must balance each other out.
4. Given that the calcium ion has a charge of +2, the sulfate ion must have a charge that balances this out to maintain neutrality.
5. Conclude that the sulfate ion (SO4) must have a charge of -2 to balance the +2 charge of the calcium ion, resulting in a neutral compound.