Atomic radii INCREASES when going DOWN a group because of more energy levels and DECREASES going ACROSS a group because of the increasing positive charge of the nucleus pulling in on the electrons.
Answer:
Explanation: A {6d+4.5e45d+4.5e=16.5=4
{6d+4.5e45d+4.5e=16.5=4
D {6d+4.5e6d+0.6e=16.5=4.8
{6d+4.5e6d+0.6e=16.5=4.8
B {30d+22.5e5d+0.5e=82.5=4
{30d+22.5e5d+0.5e=82.5=4
E {12d+9e10d+0.5e=33=8
{12d+9e10d+0.5e=33=8
C
