Question

the atom with the largest atomic radius in group 18 is -

Explanation:

Step1: Recall atomic - radius trend

Atomic radius increases down a group in the periodic table due to the addition of new electron - shells.

Step2: Identify the position of elements in Group 18

He is in the 1st period, Ne in the 2nd, Ar in the 3rd, Kr in the 4th, and Rn in the 6th period of Group 18.

Answer:

Rn