Question

match the rule... \in the ground state of an atom, electrons fill lower energy orbitals first before occupying higher levels.\ \electron pairing only occurs after all orbitals in the same sublevel have a single electron.\ \two electrons in the same orbital can not exist in the same state and will have opposite spins.\ hunds rule pauli exclusion principle aufbau principle drag

Explanation:

The Aufbau principle states that in the ground - state of an atom, electrons fill lower energy orbitals first. Hund's rule says electron pairing only occurs after all orbitals in the same sublevel have a single electron. The Pauli exclusion principle indicates that two electrons in the same orbital cannot exist in the same state and will have opposite spins.

Answer:

1. "In the ground state of an atom, electrons fill lower energy orbitals first before occupying higher levels." - AUFBau PRINCIPLE
2. "Electron pairing only occurs after all orbitals in the same sublevel have a single electron." - HUND'S RULE
3. "Two electrons in the same orbital can not exist in the same state and will have opposite spins." - PAULI EXCLUSION PRINCIPLE