Question

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

Explanation:

Step1: Recall atomic radius trend in a group

In a group (vertical column) of the periodic table, atomic radius increases as we move down the group. This is because as we go down a group, new electron shells are added.

Step2: Identify the position of given elements

Group 18 elements (noble gases) are \(He\) (helium - first period), \(Ar\) (argon - third period), \(Kr\) (krypton - fourth period), \(Rn\) (radon - sixth period).

Answer:

\(Rn\)