An atom of an element has 2 electrons in the M shell i.e., third shell. What will be the atomic number of this element ? Name this element. Find the valency of this element. Also, find the number of neutrons in the atom of this element


(i) Atomic number is 12
(ii) Element is magnesium.
(iii) Valency is 2 (+2)
(iv) No. of neutrons = Atomic mass-No. of protons
= 24 - 12 = 12