Question

The radii of \(A^{+2}\) and \(B^{-1}\) ions are 1.12 AA and 1.31AA respectively. The coordination number of \(A^{+2}\) in mineral AB\(_2\) is _________
 

Hint:

In ionic crystals, the coordination number depends on the ratio of the ionic radii. A common coordination number for \(A^{+2}\) in AB\(_2\) minerals is 6.

Answer 1

Correct Answer: 8

Step 1: Understanding Coordination Number.
The coordination number of an ion in a crystal structure is determined by the ratio of the radii of the cation (positively charged ion) to the anion (negatively charged ion). Typically, in an AB\(_2\) type mineral, the coordination number of \(A^{+2}\) is 6 when the ionic radii are similar for typical mineral structures.
Step 2: Conclusion.
Given the radii of \(A^{+2}\) and \(B^{-1}\), the coordination number of \(A^{+2}\) in mineral AB\(_2\) is 6, which is characteristic of many common ionic minerals.