Question

Decrease in size of the atom due to increase attraction between nucleus and electron is much less as compared to the increase in size due to the addition of electron shells of electrons



explanation of line

Answer 1

Yes.
Across period,the nuclear charge of atom increases.Nucleus is of positive charge and electrons are of negative charge.As the nucleus charge increases(positive),it attracts the electrons more,so,the size of the atom decreases.
Across group,the number of shells gets added up.As the no of shells gets added up,the electrons have more space and gets equally filled with each shell.As the shells increases,the distance between the valence electrons and the nucleus decreases,it cannot attract the valence shell electron efficiently.So,across group size of atom increases.