Electronic structure of atoms

• What does Bohr's model describe?

  Shapes in space where electrons are found
• How do electrons orbit the nucleus in atoms?

  In shells, with increasing energy further out
• What is the maximum number of electrons in the 1st shell?

  2
• How many electrons can the 2nd shell hold?

  8
• What is the maximum number of electrons in the 3rd shell?

  18
• How many electrons can the 4th shell hold?

  32
• What are electron configurations?

  • Arrangement of electrons in atoms or ions
  • Reflects main shells and sub-shells
• What is the electron configuration for Boron?

  1s²2s²2p¹
• What is the electron configuration for Carbon?

  1s²2s²2p²
• What is the electron configuration for Nitrogen?

  1s²2s²2p³
• How can you find the total number of electrons in an atom?

  By using the atomic number
• What does the atomic number represent?

  Number of protons in an atom
• What are atomic orbitals?

  Regions in space where electrons may be found
• How does the size of the main energy level affect orbitals?

  Larger levels have more orbitals
• What are the first four types of orbitals?

  s, p, d, and f orbitals
• What is the shape of an s-orbital?

  Spherical
• How many electrons can an s-orbital hold?

  2
• What is the shape of a p-orbital?

  Bell-shaped
• How many electrons can a p-orbital hold?

  2
• How many p orbitals are in each p shell?

  3
• What are the rules for arranging electrons?

  1. Start at the lowest shell
  2. Fill each sub-level before the next
  3. Fill each orbital singly before pairing
  4. Paired electrons have opposite spins
• What is the Aufbau principle?

  Electrons fill lower shells before higher ones
• How many elements can you write electron configurations for using spd notation?

  The first 36 elements
• What does the direction of the arrows in electron diagrams indicate?

  The spin of each electron
• How do paired electrons behave in terms of spin?

  They spin in opposite directions
• Can orbitals be confused with sub-shells?

  Yes, they can be confused
• What is the energy relationship between the 4s and 3d orbitals?

  4s is lower when empty, higher when occupied
• How do you write the electron configuration for different particles?

  • Use the number of electrons given
  • Follow the rules for arranging electrons
• What is the electron configuration for a Na atom with 11 electrons?

  1s²2s²2p⁶3s¹
• What is the electron configuration for an O^2- ion with 10 electrons?

  1s²2s²2p⁶
• What is the electron configuration for a Ti atom with 22 electrons?

  1s²2s²2p⁶3s²3p⁶4s²3d²
• What is the electron configuration for a V²⁺ ion with 20 electrons?

  1s²2s²2p⁶3s²3p⁶4s²3d³