Answer
a) Incorrect. A Roman numeral is not used with a Group A metal.
d) Incorrect. Ammonium ion (a polyatomic cation) will not form a compound with a monatomic cation.
Work Step by Step
a) Incorrect. A Roman numeral is not used with a Group A metal.
d) Incorrect. Ammonium ion (a polyatomic cation) will not form a compound with a monatomic cation.