The electronic configuration of three clements X, Y and Z are given below ,
X = 2 , Y = 2, 6 , Z = 2, 8, 2.
(i) Which element belongs to the second period ? (ii) Which element belongs to the eighteenth group ?
(iii) Which element belongs to the second group ? (iv) What is the valency of Y ?
(v) Are Y and Z metals or non-metals ?

Explanation

(i) The element 'Y' belongs to second period.
(ii) The element 'X' belongs to eighteenth group also called zero group.
(iii) The element 'Z' belongs to second group.
(iv) Elment 'Y' has valency equal to 2(8 - 6 = 2).
(v) The element 'Y' is a non-metal while element 'Z' is a metal.