These are atomic orbital designations representing the energy levels and subshells where electrons reside in an atom.
Orbital Notation Breakdown:
Number (1, 2, 3):
- Principal quantum number (n)
- Indicates the electron shell or energy level
- Higher number = farther from nucleus, higher energy
Letter (s, p, d, f):
- Angular momentum quantum number (ℓ)
- Indicates orbital shape/type
- s = 0 (spherical)
- p = 1 (dumbbell-shaped)
- d = 2 (complex shapes)
- f = 3 (more complex shapes)
Examples:
- 1s: First shell, s-orbital (holds max 2 electrons)
- 2s: Second shell, s-orbital (holds max 2 electrons)
- 2p: Second shell, p-orbitals (holds max 6 electrons in 3 orbitals)
- 3s: Third shell, s-orbital (holds max 2 electrons)
- 3p: Third shell, p-orbitals (holds max 6 electrons)
Electron Filling Order: 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p...
Key Takeaways:
- Describes electron location and energy
- Foundation of electron configuration
- Aufbau principle governs filling order
- Critical for understanding chemical bonding