Consider rubidium and nitrogen, what are the symbols for the ions and formula for the ionic compound formed between the elements?

• A. ions: Rb⁺ and N³⁻
  ionic compound: Rb₃N
• B. ions: Rb²⁺ and N³⁻
  ionic compound: Rb₃N₂
• C. ions: Rb²⁺ and N²⁻
  ionic compound: RbN
• D. ions: Rb⁺ and N²⁻
  ionic compound: Rb₂N

Answer: (A)