The electronic configuration of $\ce{Ca}$ ($Z = 20$) is:

Question

Accepted Answer

$1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,4s^2$

Answer

$1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,3d^2$

Answer

$1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,4s^1\,3d^1$

Answer

$1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,4p^2$

The electronic configuration of Ca\ce{Ca}Ca (Z=20Z = 20Z=20) is: