Question

Why does a cation tend to surround itself with as many anions as possible?

• A. To maximize entropy
• B. To maximize density
• C. To maximize stability.
• D. To minimize stability.

Answer 1

The correct option is C

To maximize stability.

We already know from close packing that crystals tend to be close packed because they try to surround themselves with as many atoms as possible. Further, this happens because a higher number of surrounding atoms leads to reduction in the potential energy of the system. The exact mechanism of how this happens is more physics than chemistry, so we won't deal with that.

Finally, a lower potential energy is known for increasing stability and we know nature loves stability!

So, a higher coordination number or a higher number of surrounding atoms or ions - anions in this case is always favored.