Concept Explanations

Quantum and Nuclear Physics

12.1 – The Interaction of Matter with Radiation

12.1.1 – The Photoelectric Effect

12.1.2 – Matter Waves

12.1.3 – Pair Production and Pair Annihilation

12.1.4 – The Bohr Model

12.1.5 – The Wave Function

12.1.6 – The Uncertainty Principle

12.1.7 – Quantum Tunnelling

Definitions to Memorize*

 

Term/Concept

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Definition/Explanation

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Video

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Photoelectric effect
  • When a metal surface is exposed to electromagnetic radiation, photons are incident on the surface.
  • The photons interact with the electrons in the metal.
  • Each photon interacts with a single electron.
  • If the energy of the photon is larger than the work function of the metal, the electron is emitted from the surface.
  • Any additional energy supplied by the photon is converted into the kinetic energy of the electron.

Video 12.1.1
Work Function of a Metal Surface

The minimum energy required to remove an electron from the metal surface

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Video 12.1.1

De Broglie Hypothesis

Matter can also have wave-like properties/behave as a wave.

Video 12.1.2

Bohr Model
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  • Electrons orbit the nuclear in circular orbits.
  • Electrons have quantized energy.
  • Electrons have quantized angular momentum.

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Video 12.1.4

Schrodinger Model
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  • Electrons do not have fixed orbits around the nucleus.
  • The position of electrons is described by the wave function, so the position of electrons is probabilistic. 
  • Electrons can be at different energy levels.

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Video 12.1.5

Quantum Tunneling

A process by which a particle is able to escape a high potential barrier.

 

Video 12.1.7

* The terms and concepts above have directly come up on past IB Physics exams from May 2016 onwards. 

Directly in this context  means that the answer to a Paper 1 or Paper 2 question was the definition of the term or concept or that the answer could be deduced directly from the definition.  Therefore, this list might be helpful when you are deciding what to memorize for your IB Physics exams.

To see a complete list of definitions from all topics along with the number of times the term/concept occured on exams since May 2016, click on the link below:

All Definitions from Past IB Exams (pdf)

Sub-topic Quiz

The Interaction of Matter with Radiation
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Other Topic Specific PaperPlainz Resources

HL Questionbank

Quantum and Nuclear Physics

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HL Past Exam Video Solutions by Topic

Quantum and Nuclear Physics

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Sub-topic 12.2 →