Calcium is an element that belongs to the second group on the periodic table. Calcium has a valency of two and would readily loose both electrons in order to achieve stability when forming bonds.
It has 20 electrons.
Calcium would favor ionic bonds when combining with other atoms and by the virtue of this, it would readily transfer its two outermost electrons. This would make its atom mimic that of Argon-18.
The correct information is given below:
Electron structure of atom: 1S²2S²2P⁶3S²3P⁶4S²
Electron structure of ion: 1S²2S²2P⁶3S²3P⁶
Net ionic charge: +2
the correct answer would be d. hope this !