Question

Out of `Tc, Rh, Zr, Y`, which element has the smallest atomic radius?

Answer 1

`"Rhodium"` has the smallest atomic radius of the given elements.

Explanation:

All of the metals derive from the 2nd row transition series. Atomic size DECREASES from left to right across a Period as we face the Table, but INCREASES down a Group.

Given the atomic numbers, atomic yttrium (`"Group 3"`) is larger than zirconium (`"Group 4"`), which is larger than technetium (`"Group 7"`), which is larger than rhodium (`"Group 9"`).

Now as a chemist, as a physical scientist, it is your job to seek out the data that inform this argument. You should look up data that compile the atomic radii of elements. I might be pulling your leg.