## Lesson 6: Matter Waves

## Overview:

Congratulations on making it this far into the course, you will find a video at the end that describes what Quantum Tunneling is, and will be able to change the way you think about the world around you. It is your responsibility as a future leader of tomorrow to change the world!

## Curriculum Expectations:

**Overall Expectations:**

**F2.**Investigate special relativity and quantum mechanics, and solve related problems.

**F3.**Demonstrate an understanding of the evidence that supports the basic concepts of quantum mechanics and Einstein’s theory of special relativity.

**Specific Expectations:**

**F1.1**Analyze the development of the two major revolutions in modern physics (e.g., the impact of the discovery of the photoelectric effect on the development of quantum mechanics; the impact of thought experiments on the development of the theory of relativity), and assess how they changed scientific thought.

**F2.1**Use appropriate terminology related to quantum mechanics and special relativity, including, but not limited to: quantum theory, photoelectric effect, matter waves, time dilation, and mass–energy transformation.

**F2.2**Solve problems related to the photoelectric effect, the Compton effect, and de Broglie’s matter waves.

**F2.4**Conduct a laboratory inquiry or computer simulation to analyse data (e.g., on emission spectra, the photoelectric effect, relativistic momentum in accelerators) that support a scientific theory related to relativity or quantum mechanics.

**F3.1**Describe the experimental evidence that supports a particle model of light (e.g., the photoelectric effect, the Compton effect, pair creation, de Broglie’s matter waves).

**F3.2**Describe the experimental evidence that supports a wave model of matter (e.g., electron diffraction).

## Success Criteria:

- What is the equation for the de Broglie wavelength and what does it mean in terms of matter?
- What are matter waves?
- Is it possible to determine the de Broglie wavelength of larger objects, such as a baseball?
- Interpret the double slit experiment with the use of: (i) collapse interpretation, (ii) pilot wave interpretation, (iii) many-worlds interpretation, and (iv) Copenhagen interpretation.

## Time Allocation: 3 hours

## Learning A

ctivities:**Read**pages 632 - 638 from Nelson 12.3 and

**copy the sample problems**into your notes.

Quantum Wave InterferenceWhen do photons, electrons, and atoms behave like particles and when do they behave like waves? Watch waves spread out and interfere as they pass through a double slit, then get detected on a screen as tiny dots. Use quantum detectors to explore how measurements change the waves and the patterns they produce on the screen. |

In the playlist below, video:

- Will show you how to use de Broglie method to calculate the wavelength of a proton.
- Will show you how to use the Heisenberg Uncertain Principle to calculate the uncertainty of a wavelength.
- A three part series from Ontario's Perimeter Institute of Theoretical Physics exploring: 'Quantum physics is considered by many to be the single most important advance in our understanding of the universe. This video introduces you to quantum physics via the double-slit experiment and the concept of wave-particle duality.'

**Practice**questions 1, 2, 3 and 4 on page 634.

## Task:

**Solve**questions 1, 2 and 3 from Nelson 12.3 Review on page 639.

Quiz Chapter 12 on Moodle.

Complete the assignment on Moodle "Explore an Application in Quantum Mechanics."

*Optional Extension:*- Solve questions 3 and 8 on page 253.

## Reflect:

Describe the experimental evidence that supports a wave model of matter (e.g., electron diffraction).