(a) How does the size of atom of elements very down a group in the periodic table? Why is it so?

(b) What does the tendency to lose electrons vary down a group in the periodic table? Give reason.

(a) When we go down in a group, the new shell of electrons is added at every step due to which the size of the atoms increases.

(b)Since one energy shell is added at every step due to which the distance between the valence electrons and the nucleus increases and forces of attraction decreases. This results in increase in the tendency to lose electrons down the group.