Answer:
1s2 2s2 2p6 3s2 3p6
Explanation:
Calcium is the 20th element. It has 20 electrons in it's neutral state. The electronic configuration is given as;
1s2 2s2 2p6 3s2 3p6 4s2
However in the compound; calcium chloride, it does not exist in it's neutral state.
CaCl2 --> Ca2+ + Cl-
In Ca2+ state, it has lost two electrons, The total number of electrons becomes; 20 - 2 = 18 electrons.
The electronic configuration is given as;
1s2 2s2 2p6 3s2 3p6
