Question

How to find valency?

Answer 1

to find velocity u have to se the no of ecetrons in outermost shell.. for example confrigation of sodium atom is 2,8,1.. the valency will be -1. as it is more continent to loose 1 electron then to gain 7 electron to complete octet. similarly chlorine have conf. 2,8,7. so it will gain one electron to completely octet