Write the abbreviated electron configurations for Calcium and the Calcium ion. Write the abbreviated electron configuration for Sulfur and Sulfide. Determine what each ion is isoelectric with.

Question

Calcium: _______

Calcium ion:______

isoelectric with:_______

Sulfur:______

Sulfide:______

isoelectric with:_______

Answer 1

First, how many electrons does calcium have? It's atomic number is 20; this means that it has 20 protons and 20 electrons.

By abbreviated, one assumes that we would start with the previous noble case. In the case of calcium, that would be argon.

So Calcium's abbreviated electron structure would be [Ar] 4s² (because it is in the 2nd column and on the 4th row). As Calcium is a metal, it loses electrons to become an ion. So it would lose the 2 electrons. That would make its abbreviated electron structure simply [Ar]. The calcium ion has 18 electrons so it is isoelectronic with Argon.

We would do something similar with Sulfur. Sulfur has 16 electrons - so its structure would be [Ne] 3s² 3p⁶; it would gain 2 electrons to become an ion (non-metals gain), so its ion structure would be [Ne] 3s² 3p⁸ and that makes it also isoelectronic with Argon.