Question

An element x belong to 3 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 element y atomic number 8 C write the name and formula of the compound formed when x combine with chlorine

Answer 1

A.It is the element Aluminium,
valency electrons are 3 present in 3rd shell.and valency is 3 as three electrons are to be removed to attain stability.
B.Molecular formula when reacts with at.no.8 is Al2O3.
C.formula=AlCl3,
Name=aluminium chloride.

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