Question

what the trend of valency in periodic table when we move in a group or in a period​

Answer 1

Answer:

valency first increases and then decreases in a period .no change down the group

Answer 2

Answer:

In periods : In period as atomic number increases from left to right, the valence

increases from 1 to 4 and then decrease from 4 to zero.

In groups : Down the group valence remains same as all the elements possess the same number of valence electrons.