Question

which of the following elements has a ground-state electron configuration different from the predicted one? group of answer choices cu ca ti cl xe

Answer 1

The elements with different ground-state electron configurations than predicted are Cr and Cu.

Step-by-step explanation:

In the case of Cr and Cu, there are exceptions to the predicted ground-state electron configurations. Cr has a ground-state electron configuration of [Ar]4s²3d⁴ instead of the predicted [Ar]4s¹3d⁵. Cu has a ground-state electron configuration of [Ar]4s¹3d¹⁰ instead of the predicted [Ar]4s²3d⁹. These exceptions occur because half-filled and completely filled subshells represent conditions of preferred stability. In these cases, electrons are shifted from the 4s into the 3d orbital to gain extra stability.

Answer 2

Step-by-step explanation:

Copper (Cu) has a ground-state electron configuration different from the predicted one. The predicted electron configuration for copper is [Ar] 3d^9 4s^2, but the actual ground-state electron configuration is [Ar] 3d^10 4s^1. This is because copper has a half-filled d subshell, which is more stable than a partially filled subshell.