Electron Configuration Lecture Notes

Introduction

• Tutor: Melissa Marabou
• Topic Overview: Understanding electron configuration and how to write it for different elements.

Basic Concepts

• Electron Configuration: Arrangement of electrons in atomic orbitals.
• Subshells:
  • S Subshell:
    • 1 orbital
    • Holds up to 2 electrons
  • P Subshell:
    • 3 orbitals
    • Holds up to 6 electrons
  • D Subshell:
    • 5 orbitals
    • Holds up to 10 electrons
  • F Subshell:
    • 7 orbitals
    • Holds up to 14 electrons

Periodic Table Blocks

• S Block: First two groups + helium
• P Block: Opposite side of S block
• D Block: Inner transition metals
• F Block: Bottom of the periodic table

Electron Configuration Order

• Order is crucial: Follow a specific sequence from hydrogen.

Examples

Example 1: S Block

• Element: Beryllium
• Process:
  • Start from hydrogen: 1s1
  • Helium: 1s2
  • Beryllium: 2s2
• Configuration: 1s2 2s2

Example 2: P Block

• Element: Sulfur
• Process:
  • Hydrogen to Helium: 1s2
  • Second row S block: 2s2
  • P Block: 2p6
  • Third row S block: 3s2
  • Third row P block to sulfur: 3p4
• Full Configuration: 1s2 2s2 2p6 3s2 3p4
• Condensed Configuration:
  • Noble Gas: Neon
  • After Neon: 3s2 3p4

Example 3: D Block

• Element: Iron
• Process:
  • Follow sequence up to 4s2
  • D block: 3d6
• Full Configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d6
• Condensed Configuration:
  • Noble Gas: Argon
  • After Argon: 4s2 3d6

Example 4: F Block

• Element: Plutonium
• Process:
  • Sequence to F block: 4f14
  • Continue to 5d10, 6p6, 7s2
  • F block again: 5f6
• Full Configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f6
• Condensed Configuration:
  • Noble Gas: Radon
  • After Radon: 7s2 5f6

Additional Resources

• Homework Help: Available online
• Practice Quiz: Video available with step-by-step answers
• Encouragement: Stay determined, you can do this!