Question

do we need to write the valency with a positive or negative charge or just the number​

Answer 1

Answer:

it is very important to write valency

Answer 2

Answer:

while making a chemical formula, we dont need to mention the positive or negative charge on the number but while just mentioning about the valency , we need to mention the negative or positive charge in order to determine whether the ion lossed, gained or shared the electrons.

hope it helps...