Question

give reason why NH3 is a base?

Answer 1

NH3 contains 1 molecule of nitrogen and 3 molecules of hydrogen. More hydrogen makes a chemical basic.
Therefore ammonia or NH3 is a base

Answer 2

For NH3 to be a Lewis base, it would have to react in such a way that a lone pair on it attached itself to another atom or molecule. It turns out that ammonia tends to very readily donate its electron .........