Question

how does number of valence electons and valency vary on moving from left to right in the second period of a periodic table

Answer 1

when we move from left to rigelectronsht in any period the valency frst increase then decreases till zero and the shell number is constant but the valence electrons are changed.

Answer 2

When we move from left to right in the second period of the peroidic table the valency first increases and then decreases to zero. But the valence electrons remain consant in second periodic table when we move from left to right in second period.