What happens to the atomic size of the elements as one goes from the bottom to the top of a group?

a) atomic size stays the same as one moves from bottom to top in a group.

b) atomic size decreases as one moves from bottom to top in a group.

c) atomic size increases as one moves from bottom to top in a group.

d) atomic size changes randomly as one moves from bottom to top in a group.

Option (B) is the correct answer.

Explanation:

When we move from top to bottom in a group then size of elements keep of increasing due to the addition of more number of electrons into new shells.

But when we move across a period then there occurs a decrease in size of the elements due to the addition of electrons into the same shell.

So, if we move from bottom to top then it means there is decrease in size of atoms as number of electrons decreases then.

Thus, we can conclude that atomic size decreases as one moves from bottom to top in a group.