Question

An element 'X' belong to 3rd period and group 13 of the Modern Periodic Table.

(a) Determine the valence electrons and the valency of 'X'.

(b) Molecular formula of the compound formed when 'X' reacts with an element 'Y' (atomic number = 8).

(c) Write the name and formula of the compound formed when 'X' combines with chlorine

Answer 1

Period of X = 3

Group of X = 13

Atomic number of X = 13

Electronic configuration: 2, 8, 3

(a) Number of valence electrons = 3 and valency = 3

(b) Atomic number of Y = 8

Electronic configuration = 2, 6

Valency of Y = 2

Molecular formula of the compound formed when ‘X’ reacts with an element ‘Y’ is X₂Y₃.

(c) Atomic number of Cl = 17

Electronic configuration = 2, 8, 7

Valency of Y = 1

Molecular formula of the compound formed when ‘X’ reacts with an element ‘Y’ is XCl₃