Given Any Two Elements Within A Group, Is The Element With The Larger Atomic Number Likely To Have A Larger Or Smaller Atomic Radius Than The Other Element?

The atomic radius decreases across a period from left to right and
increases down in a given group. That means that since the lower the element is in a group, the larger the atomic radius will be.  The atoms with the largest atomic radii
are located in Group I and are at the bottom of groups.