Question

An element belongs to third period and second group in the periodic table.
(a) State number of valence electrons in it. (b) Is it a metal or non-metal ?
(c) Name the element (d) Write the formula of its oxide

Answer 1

(a) The element belonging to third period and second group is calcium (Z = 20). Its electronic configuration is 2, 8, 8, 2
(a) It has two valence electrons (b) The element is a metal
(c) The element is calcium (Ca) (d) The formula of calcium oxide is CaO.