SCH4U - Chemistry 12 (2024-25) - A

Lesson Summary:

• Atoms are made up of protons, neutrons, electrons and empty space
• Rutherford and Bohr were 2 important scientists who contributed to our knowledge of how atoms are structured
• Rutherford’s Gold Foil Experiment Conclusions:
  • Protons and neutrons are confined to a small space at the center of an atom (the nucleus)
  • Electrons surround the nucleus with empty space in between the electrons and the nucleus
• Bohr’s conclusions from the Hydrogen emission spectrum:
  • Electrons orbit the nucleus in defined energy levels called orbits
    
  • Orbits have increasing energy associated with them the further away from the nucleus they are
  • Electrons can jump to higher orbitals by absorbing energy
    
  • Electrons want to be in the lowest energy state possible, therefore in the lowest possible orbital, this is known as the ground state
  • When electrons drop from a higher energy orbital to a lower energy orbital, energy is emitted in the form of a photon, and these photons form the individual lines of the emission spectrum for hydrogen