Question

WHY ATOMIC SIZE OF GRP 18 ELEMENTS IS
GREATER THAN GRP 17 ELEMENTS?​

Answer 1

Correct Question:-

Why atomic size of group 18 elements is greater than group 17 elements?

Your Answer:-

As 18 group elements are inert gas that is there orbits are full. And in the 17 group elements the orbits are not completely full. As we know negative attracts positive, Similarly the electrons in 17 group elements attracts protons to them. This leads to smaller the atomic radius of 17 group elements. But in 18 group elements the protons are more than that of 17 group elements. So that's why the attractive force by electron on proton of group 18 elements is less than group 17 elements. So, group 18 elements have large atomic radius than group 17 elements.