Question

____ has the smallest atomic radius.
a silicon
b tin
c lead
d germanium

Explanation:

Atomic radius increases down a group in the periodic table. Silicon (Si), Tin (Sn), Lead (Pb), and Germanium (Ge) are all in Group 14. Silicon is the highest up in the group among them, so it has the smallest atomic radius due to fewer electron - shells compared to the others.

Answer:

a. Silicon