Answer : 'Sb' is the element which has the greatest atomic radius.
Explanation :
The general trend of the atomic radium of the element is that,
As we are going from left to right in a periodic table the atomic radius of the elements decreases and as we are going from top to bottom in a periodic table the atomic radius of the elements increases.
The given elements are the group 15 elements in which the 'Sb' is the element which has the greatest atomic radius as compared to N, P and As because as we are going from top to bottom in group 15 the the atomic radius of the elements increases that means the number of energy shells increases.
Hence, 'Sb' is the element which has the greatest atomic radius.
