A 2, 8, 8
B 2, 8, 2
C 2, 6
D 2, 8
Which electronic configuration represents:
(i) magnesium atom?
(ii) oxygen atom?
(iii) sodium ion?
(iv) chloride ion?
(ii) C will be the desired answer as atomic number of oxygen atom is 8.
(iii) D represents the sodium ion, as it has E.C of 2,8.
(iv) A represents chloride ion because it has E.C of 2, 8, 8.