Question

1 explain why atomic radiums of ga is smaller as compared to al

Answer 1

Acoorring to Periodic trend atomic radius of Al should be less than Ga.

But from Al to Ga, there is an intervining filled d-rbital present for Ga. d-orbital has low shielding effect and exposes valence electrons more to increased effective nuclear charge of Ga, while Al has no d-orbital and less relative effective nuclear charge. Thus valence shell of Ga experiances high attraction of nucleus and shrinks in size