1. The Aufbau principle states that electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels.
2. The diagram shows the order of orbital filling based on increasing energy: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.
3. Electrons are placed in orbitals according to this sequence, with each orbital holding a maximum of two electrons (Pauli exclusion principle).
4. The arrows indicate electron occupancy: 1s², 2s², 2p⁶ — meaning the 1s and 2s orbitals are fully filled, and the 2p orbitals contain six electrons (three orbitals, two each).
5. The next electron would enter the 3s orbital, following the energy order shown.
Parent Tip: Review the logic above to help your child master the concept of orbital diagram worksheet.
