Which atom in the ground state has the same electron configuration as a calcium ion, $Ca^(2+)$ in the ground state?

Question

10806 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-04-19T16:40:22

The preceding Noble Gas.

Calcium, $Z=20$ , has 20 electrons as the neutral atom. $Ca^(2+)$ necessarily has 18 electrons. The preceding Noble $Z=20-2=18$ is argon, $Ar$ .

Which atom in the ground state has the same electron configuration as a calcium ion, Ca^(2+)Ca^(2+) in the ground state?