Which element has the largest atomic radius?
a.) as b.) n c.) p d.) sb

The correct option is (D).

Explanation:

In a periodic table when we move down the group, size of an atom increases with increase in atomic radii. This is because on moving down the group new shell is added due to which valence electrons moves far away from the nucleus.

Given elements in options are members of the same group that is group 15 in which nitrogen (N) is first member followed by phosphorus (P), arsenic(As) and tin(Sb).Here tin is the last member.

Hence, tin(Sb) has the largest atomic radius.

This is because in a group, the properties are alike. Remember one thing and you will pass your examsthat the properties of an element are determined by its electrons, aka valence electrons, and the valence electrons of a group are the same.