Answer:
[Ar]4s²
Explanation:
The electronic configuration of calcium is given as follows;
1s²2s²2p⁶3s²3p⁶4s²
The electronic configuration of argon, Ar is 1s²2s²2p⁶3s²3p⁶
Given, that there is a similarity be tween the electronic configuration of all the shells of the an atoms of argon and an atom calcium, except for the added valence shell electrons in calcium, the electronic configuration of calcium can be represented by the symbol of an atom of argon, followed by the electonic configuration of the valence shell as follows
The electronic configuration of calcium with argon as base = [Ar]4s².
