Compare the radius of a nonmetal atom with the radius of its ion. (ex: cl vs. cl^-1)

Radius of ion is more than

Explanation:

Radius of atom : It depicts the size of the atom . Distance from the centre of the nucleus to the outermost shell of the atom.

= Effective nuclear charge : It is the total positive charge of nucleus felt by the valence electron. Greater the , smaller is the size of the atom ,since electron get held tightly toward nucleus.

: It's radius is 99 pm (picometer) .It has atomic number 17 . 17 proton are holding 17 electrons

: It's radius is 181 pm. 17 proton are holding 18 electrons

Reason for increase in size from to  .

is formed when one electron is added to Cl atom.This causes more electron-electron repulsion within the shell.The attractive force of the nucleus reduce because decreases.