Electron Configuration

• What are the terms defined in the learning outcomes?

  Sub-shell, orbital, and spin
• What does the Aufbau principle explain?

  How electrons fill orbitals based on energy
• What does the Bohr model state about electrons?

  Electrons orbit the nucleus in set orbits
• How is energy related to electron shells in the Bohr model?

  Lowest energy is in the smallest shell
• What happens when an electron moves between shells?

  Radiation is absorbed or emitted
• What are the names of the sub-shells?

  s, p, d, and f
• How many electrons can each orbital hold?

  2 electrons with opposite spin
• What is the structure of electron shells and sub-shells?

  • Main electron shell contains sub-shells
  • Sub-shells:
  • 1: s
  • 2: s, p
  • 3: s, p, d
  • 4: s, p, d, f
  • Each sub-shell has specific orbitals and electron capacity
• What is the rule for filling orbitals in electron configuration?

  Electrons occupy lowest energy orbitals first
• How are electrons represented in orbital diagrams?

  As half arrows
• What is the maximum number of electrons in an orbital?

  Two electrons maximum
• What is the order of filling orbitals in the same sub-shell?

  Occupy singularly before doubling up
• Which sub-shell fills before the 3d sub-shell?

  4s sub-shell
• What does Hund's Rule state?

  Every orbital is singly occupied first
• What is the spin of electrons in singly occupied orbitals?

  All have the same spin
• How do you write the electron configuration for Lithium?

  • 1s² 2s¹
• How do you write the electron configuration for Fluorine?

  • 1s² 2s² 2p⁵
• What does the Aufbau principle ensure for electron configuration?

  Most stable electron configuration possible
• What are the learning outcomes of this section?

  Define sub-shell, orbital, and spin