a) How does electropositivity of elements get affected as we move: (i) down a group (ii) across a period?
b] Which atomic property increases as we move across a period and down a group?

Explanation

a] Electropositivity of elements (i) increases down a group and (ii) decreases as we move from left to right across a period. 
b] The atomic number and hence the number of electrons (and protons) increases both across a period and down a group.