Question

Which of the following statements are correct?
I) The van der Waals radius is nearly 40% less than the covalent radius.
II) The atomic radius of neon is more than fluorine.
III) The decrease in atomic radius is more when second electron enters into s-subshell.

• A. I and II
• B. I and III
• C. II and III
• D. I, II and III

Answer 1

The correct option is C II and III

A) The van der Waals radius is nearly 40% greater than the covalent radius, as it is measured in a non-bonding condition.

B) In a period, size decreases on going from left to right due to an increase in effective nuclear charge. Thus, alkali metals have large atomic radii and halogens have the smallest size.
The atomic radius of neon is greater than that of fluorine. Halogens have the smallest size in a particular period while noble gases have the largest size, as their van der Waals radius is measured, which is the largest.

C) When the second electron enters in s-subshell, the nucleus experiences a higher effective nuclear charge and there is more contraction in their size.