Question

An element ‘X’ belongs to third period and second group of the Modern Periodic Table. (a) Write its electronic configuration. (b) Is it a metal or non-metal ? Why? (c) Write the formula of the compound formed when ’X’ reacts with an element (i) Y of electronic configuration 2, 6 and (ii) Z with electronic configuration 2, 8, 7.

Answer 1

Element is Magnesium
a) electronic configuration-- 2,8,2
b) It is metal
c)
i) compound formed will be. XY
ii) Compund will be XZ2

Answer 2

Answers to the questions are given below -

(a) Electronic configuration of given compound will be - 2,8,2.

(b) Given compound is metal. Since the compound belongs to third period and second group which is known as alkaline earth metal, our compound will be metal.

Metals are the type of compounds which are good conductors of electricity.

(c) Valency of given compound according to its electronic configuration will be - +2.

(i) Y has electronic configuration 2,6 hence it's valency will be - -2.

Hence, chemical formula will be -

XY

(ii) Z has electronic configuration 2,8,7 hence it's valency will be - -1

Hence, chemical formula will be -

XZ2