Is thw positive valence of AlCl3 1 or 3 why?

Answer 1

I don't know that AlCl3 has any valence. Al is +3 and Cl is -1. AlCl3 is zero charged.
Al has three electrons in the outside and it will lose those three electrons to become trivalent. Another way to look at it:
All compounds are zero. Since Cl is -1 and there are three of them for a -3 charge, then Al must be +3 to maintain a zero for AlCl3.

Answer 2

Plz tell that how can we say that Al is +3 not boron as boron has also 3 valency 😕???

Answer 3

As + sign denote that the element have lost electrons.