1. Basic Aufbau Principle:
* Fill orbitals in order of increasing energy levels.
* Follow the diagonal rule (the "arrow" pattern) to determine orbital filling order.
2. Orbital Filling Order:
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p
3. Electron Configuration of Nobelium (No):
* [Rn] 5f¹⁴ 6d² 7s²
Explanation:
* [Rn] represents the electron configuration of Radon, the previous noble gas.
* 5f¹⁴ fills the 5f orbitals with 14 electrons.
* 6d² fills the 6d orbitals with 2 electrons.
* 7s² fills the 7s orbitals with 2 electrons.
Therefore, the complete electron configuration for nobelium is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d² 7s²
