Question

An element 'X' belong to 31d 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

(a) there are 3 valence electrons in an element from group 13 and it's valence is 3.

(b)when X reacts with Y galium oxide is formed (Ga2O3).

(c) when X combines with chlorine then gallium chloride is formed . Its formula is GaCl3.

Answer 2

Answer:

Given :

X belongs to period 3rd and group 13th.

Atomic number of X is 13.

Electronic configuration of X

= > 2 , 8 , 3

a ) .

Valance electron in 'X' is 3 .

Valency is 3 as it denote 3 electron to become stable.

b ) .

Given :

Atomic number of Y is 8

Electronic configuration of Y :

= > 2 , 6

Valency of Y is 2 as it need 2 electron to become stable.

Molecular formula X with Y is as :

X     Y

3    2

= > X₂Y₃

c ) .

Valency of X = 3

Valency of Cl = 1

Molecular formula of X with Cl :

X    Cl

3     1

= > XCl₃