DP Physics (last assessment 2024)
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7.3 – The structure of matter

Description

Nature of science:

Predictions: Our present understanding of matter is called the Standard Model, consisting of six quarks and six leptons. Quarks were postulated on a completely mathematical basis in order to explain patterns in properties of particles. (1.9)

Collaboration: It was much later that large-scale collaborative experimentation led to the discovery of the predicted fundamental particles. (4.3)

Understandings:

  • Quarks, leptons and their antiparticles
  • Hadrons, baryons and mesons
  • The conservation laws of charge, baryon number, lepton number and strangeness
  • The nature and range of the strong nuclear force, weak nuclear force and electromagnetic force
  • Exchange particles
  • Feynman diagrams
  • Confinement
  • The Higgs boson

Applications and skills:

  • Describing the Rutherford-Geiger-Marsden experiment that led to the discovery of the nucleus
  • Applying conservation laws in particle reactions
  • Describing protons and neutrons in terms of quarks
  • Comparing the interaction strengths of the fundamental forces, including gravity
  • Describing the mediation of the fundamental forces through exchange particles
  • Sketching and interpreting simple Feynman diagrams
  • Describing why free quarks are not observed

Guidance:

  • A qualitative description of the standard model is required

Data booklet reference:

 

International-mindedness:

  • Research into particle physics requires ever-increasing funding, leading to debates in governments and international research organizations on the fair allocation of precious financial resources

Theory of knowledge:

  • Does the belief in the existence of fundamental particles mean that it is justifiable to see physics as being more important than other areas of knowledge?

Utilization:

  • An understanding of particle physics is needed to determine the final fate of the universe (see Physics option sub-topics D.3 and D.4)

Aims:

  • Aim 1: the research that deals with the fundamental structure of matter is international in nature and is a challenging and stimulating adventure for those who take part
  • Aim 4: particle physics involves the analysis and evaluation of very large amounts of data
  • Aim 6: students could investigate the scattering angle of alpha particles as a function of the aiming error, or the minimum distance of approach as a function of the initial kinetic energy of the alpha particle
  • Aim 8: scientific and government organizations are asked if the funding for particle physics research could be spent on other research or social needs

Directly related questions


Sub sections and their related questions

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