CHEMISTRY COMMUNITY

What is Hund's rule and how is it relevant to electron orbitals? What would happen if the orbitals had opposite spin?

Hund's Rule basically states that every orbital shell is to be occupied by an electron before any orbital is occupied with two electrons. Usually this means that one spin direction is occupied for all the orbital shells before the opposite spin direction occupies the orbital to fill the shells.

Hund's Rule states that due to electron repulsion, electrons in the same subshell occupy different orbitals with parallel spin. This allows for the lowest possible energy state. There are no more than two electrons per orbital. If 2 electrons are in the same orbital they are spin paired.

To add on to the previous reply, Pauli Exclusion Principle states that there can be no more than 2 electrons per orbital and that if 2 electrons are in the same orbital then they spin paired.

what exactly does it mean for an electron to be be spin paired?

For an electron to be spin paired means that one electron within the orbital has a counterclockwise spin, while the other electron occupying that orbital has a clockwise spin.

Spins basically just shows which direction the electron is going in. Counter clockwise or clockwise.