Which of the following is the correct formula for the ionic compound formed between strontium ions and nitrogen ions?

• A. SrN2
• B. SrN
• C. Sr3N2
• D. Sr2N3

Answer: (C)

Verified step by step guidance

1. Identify the charges of the ions involved: Strontium (Sr) typically forms a +2 charge as Sr^{2+}, and nitrogen (N) typically forms a -3 charge as N^{3-}.
2. Determine the ratio of ions needed to balance the total positive and negative charges so that the compound is electrically neutral.
3. Set up the charge balance equation: Let the number of Sr^{2+} ions be x and the number of N^{3-} ions be y. The total positive charge is 2x and the total negative charge is -3y. For neutrality, 2x = 3y.
4. Find the smallest whole number ratio of x to y that satisfies 2x = 3y. This ratio is x = 3 and y = 2, meaning 3 Sr^{2+} ions combine with 2 N^{3-} ions.
5. Write the formula using the ratio found: Sr_{3}N_{2}.