Question

If the radius of an element X of electronic configuration 2, 8, 3 is $0.76$ $A^0$, the radius of element Y of electronic configuration 2, 8, 5 will be :

• A. $0.64$ $A^0$
• B. $0.76$ $A^0$
• C. $0.88$ $A^0$
• D. $1.08$ $A^0$

Answer 1

The correct option is A $0.64$ $A^0$

Given :

EC of X is 2, 8, 3
EC of Y is 2, 8, 5 since they belong to same period, atomic size decreases from left to right.

Element X is to the left of element Y.

Hence, atomic radius of Y is less than ${0.76}^{o}A$ i.e., ${0.64}^{o}A$.

Hence, option (A) is the correct answer.