An atom has 5 electrons in its outer shell. how many unpaired electrons does it have?

The answer is 3.

That is if an atom has 5 electrons in its outer shell, then it has 3 unpaired electrons.

As the outer shell have 1 s orbital too and that is fully filled and not available for bonding so it must have 3 unpaired electrons.

So the number of unpaired electrons in an atom that is having 5 electrons in its outer shell is 3.