Question

Which of the following has the maximum covalent radii?

• A. C
• B. Si
• C. Ge
• D. Sn

Answer 1

The correct option is D

Sn

Do you remember periodic classification of elements?
In that we discussed about the trends in atomic radii.
Let's take a look at the elements of the group 14.
In group 14 elements, there is a considerable increase in the covalent radius from C to Si; thereafter, from Si to Pb, a small increase in radius is observed. This is due to the addition of a new shell in each succeeding element. The increase in radii from Si to Pb is small due to ineffective shielding of the valence shell electrons by the intervening fully filled lesser shielding d- and/or f-orbitals.
Therefore we can conclude that atomic radii increase down the group.

So Sn is the correct option.