Bleep help please, I'm doing an exam.

I think it's 40N

Explanation:

because you add the forces together. If they were going in opposite directions, they'd cancel out, but because they're going the same direction, you add them. So, 20N+20N=40N

if two electrons have the same n, the same ℓ, and the same ml, then they are in the same orbital. the pauli exclusion principle states that no two identical fermions (a fancy word for electrons and other subatomic particles like electrons) may occupy the same quantum state in an atom simultaneously.

particle   p is an electron and particle q is a neutron