Question

how to find valancy from valance electrons in a periodic table​

Answer 1

Answer:

if the valance electrons are more than 5 then the electron will try to gain

therefore we should minus / subtract the number of valance electrons from 8 to get the answer

but if the electrons are less than 5 then the electron will try to lose it to achieve the nearest noble gas configuration

also, there are some execption of these cases that is why they show variation in their valency for example phosphorus, its valency can be 5 or 3 depending on what is reacting with it.