Back to Course

HSC Physics

0% Complete
0/54 Steps
  1. Module 1: Kinematics
    1.1 Motion in a Straight Line
  2. 1.2 Motion on a Plane
  3. Module 2: Dynamics
    2.1 Forces
  4. 2.2 Forces, Acceleration and Energy
  5. 2.3 Momentum, Energy and Simple Systems
  6. Module 3: Waves and Thermodynamics
    3.1 Wave Properties
  7. 3.2 Wave Behaviour
  8. 3.3 Sound Waves
  9. 3.4 Ray Model of Light
  10. 3.5 Thermodynamics
  11. Module 4: Electricity and Magnetism
    4.1 Electrostatics
  12. 4.2 Electric Circuits
  13. 4.3 Magnetism
  14. Module 5: Advanced Mechanics
    5.1 Projectile Motion
  15. 5.2 Circular Motion
  16. 5.3 Motion in Gravitational Fields
    2 Topics
  17. Module 6: Electromagnetism
    6.1 Charged Particles, Conductors and Electric and Magnetic Fields
  18. 6.2 The Motor Effect
    1 Topic
  19. 6.3 Electromagnetic Induction
  20. 6.4 Applications of the Motor Effect
    1 Topic
  21. Module 7: The Nature of Light
    7.1 Electromagnetic Spectrum
    3 Topics
  22. 7.2 Light: Wave Model
  23. 7.3 Light: Quantum Model
    2 Topics
  24. 7.4 Light and Special Relativity
  25. Module 8: From the Universe to the Atom
    8.1 Origins of the Elements
    5 Topics
  26. 8.2 Structure of the Atom
    3 Topics
  27. 8.3 Quantum Mechanical Nature of the Atom
    2 Topics
  28. 8.4 Properties of the Nucleus
    2 Topics
  29. 8.5 Deep Inside the Atom
    4 Topics
Lesson 29, Topic 1
In Progress

Subatomic Particles

Lesson Progress
0% Complete

In 1932, with the discovery of the neutron, the three basic constituents of an atom had been found. But in the same year a positive electron was discovered using cosmic rays.

Cosmic rays are very high-energy, charged particles that are produced in the Sun and other stars that continually bombard the Earth. Before particle accelerators were developed, cosmic rays were sued to examine high-energy nuclear collisions.

In the 1930s and 1940s, several new subatomic particles were discovered using cosmic rays. With the development of high-energy particle accelerators in the 1950s and 1960s, over 200 new subatomic particles were created in particle collisions. These short-lived particles were comparatively large (like neutrons and protons) and were called hadrons. Physicists initially thought all the new particles were fundamental particles but later discovered they were composed of more fundamental particles called quarks.

Murray Gell-Mann

  • Fired electrons into nucleus
  • Analysed kinetic energy, which should have been conserved through the collision (law of conservation of energy)
  • Found the energy had been scattered (in a similar pattern to Rutherford’s gold foil experiment
  • Concluded that there must be 3 points within the neutron causing this scattering, realising the neutron could not be a single solid particle
  • Phenomenon now known as Deep Inelastic Scattering