Electron Configuration

Introduction to Electron Configuration

• Electron configuration describes the distribution of electrons in an atom.

• Utilises the periodic table to identify orbitals and their corresponding energy levels.

Structure of the Periodic Table

• Periodic table arranged in periods (energy shells) and columns (orbitals).

• Each period corresponds to an energy shell, while columns indicate types of orbitals:

  • s, p, d, f orbitals.

Example: Nitrogen's Electron Configuration

• Begin by locating nitrogen in the periodic table.

• Follow the rule to read from top to bottom, left to right.

period 1:

• Orbitals Available: Only s.

• Maximum Electrons in s: 2.

• Electron Configuration Contribution: 1s² (2 electrons).

period 2:

• Orbitals Available: s and p.

• Maximum Electrons in s: 2.

• Maximum Electrons in p: 6.

• Electron Configuration Contribution: 2s² 2p.

Identifying Electrons in Nitrogen:

• In the case of nitrogen, focus on the p orbital:

  • Step to 2p: Count sequentially through the elements:

    • Boron (1 electron in 2p)

    • Carbon (2 electrons in 2p)

    • Nitrogen (3rd electron in 2p)

• Thus nitrogen's electron configuration up to 2p³ is noted.

Final Electron Configuration of Nitrogen

• Complete expression for nitrogen: 1s² 2s² 2p³

• This indicates nitrogen has a total of 7 electrons: 2 in the 1s, 2 in the 2s, and 3 in the 2p.