Question

element A has 7 electrons in L shell . Element B has 2 electrons in M shell . Which of the following represents the correct molecular formula for A and B.
a)AB
b)BA
c)B^2A
d)BA^2​

Answer 1

Answer:

AB IS THE CORRECT ANSWER

HOPE IT WILL HELP YOU

Answer 2

Answer:

The molecular formula for A and B observed is $A_{2}B$ or $BA_{2}$.

Therefore, option d) $BA_{2}$ is correct.

Explanation:

Given data,

The electrons present in the L-shell of the element A = $7$

The electrons present in the M-shell of the element B = $2$

The molecular formula for A and B =?

As we know,

Shells    Electrons present in each shell

K                           $2$

L                           $8$

M                         $18$

N                          $32$

As given,

• The electrons present in the L-shell of the element A = $7$

Therefore,

• The electronic configuration = $2,7$

And, the valency = $1$

Also,

• The electrons present in the M-shell of the element B = $2$

Therefore,

• The electronic configuration = $2,8,2$

And, the valency = $2$

Thus,

• The valency of A = 1 and the valency of B = 2

By the cross-valency method, the molecular formula is $A_{2}B$ or $BA_{2}$.