Question

1. the pauli exclusion principle states that in order to occupy the same orbital, two electrons must

fill the energy levels in order from low to high
spin in the same direction
spin in opposite directions
fill the lowest orbital first with two electrons

Explanation:

The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of four quantum - numbers. In the context of electrons in the same orbital, this means they must have opposite spins (spin quantum numbers of +1/2 and - 1/2).

Answer:

Spin in opposite directions