Question

which of the following is the largest sized atom ? a) si b)p c)al d)s

Answer 1

Atomic radius: Atomic radius decreases in going from left to right across a period. This decrease can be explained in term of the increasing effective nuclear charge in going from left to right. This means that the valence electrons are down closer to the nucleus, decreasing the size of atom. Atomic radius increases down a group, because of the increases in the orbital sizes in successive principal quantum levels.

Si, P , Al and S all present in the    

Al, > Si > P > S

Because  Atomic radius decreases in going from left to right across a period

Hence Al is the largest size atom