Quantum Physics: An Introduction
Summary
In this interactive lesson the students will be introduced to Quantum Physics. They will be introduced to wave/particle duality, Heisenburg Uncertainty Principle, superposition, Schrodinger's cat, and wavefunction.
CollapseLearning Goals
The students will understand:
- That Newtonian mechanics do not apply to the atomic world
- That waves have particle attributes and particles have wave attributes
- That all matter has a wavelength that is dependent upon its mass
- That Heisenberg's Uncertainty Principle shows that we cannot know both velocity and position of quantum entities at the same time
- That quantum particles display superposition
- Schrodinger's cat is an analogy describing superposition
- That wavefunction is a mathematical explanation of the probability of the location of a quantum particle
- That a wavefunction can be the sum of two or more differing wavefunctions
The students will be able to:
- Explain the concept of superposition
- Describe Planck's constant
- Explain why scientists cannot know simultaneously both velocity and position of quantum particles
- Describe the attributes of waves and particles
- Explain why Newtonian mechanics do not apply to the quantum world
- Explain why we don't diffract but quantum particles do
- That Newtonian mechanics do not apply to the atomic world
- That waves have particle attributes and particles have wave attributes
- That all matter has a wavelength that is dependent upon its mass
- That Heisenberg's Uncertainty Principle shows that we cannot know both velocity and position of quantum entities at the same time
- That quantum particles display superposition
- Schrodinger's cat is an analogy describing superposition
- That wavefunction is a mathematical explanation of the probability of the location of a quantum particle
- That a wavefunction can be the sum of two or more differing wavefunctions
The students will be able to:
- Explain the concept of superposition
- Describe Planck's constant
- Explain why scientists cannot know simultaneously both velocity and position of quantum particles
- Describe the attributes of waves and particles
- Explain why Newtonian mechanics do not apply to the quantum world
- Explain why we don't diffract but quantum particles do
Context for Use
This is an interactive demonstration for high school students showing Heisenberg's Uncertainty Principle, wave/particle duality, Planck's Constant, de Broglie wavelength, and how Newton's Laws go right out the window on a quantum level.
You need to allow about 15-20 minutes for the activity.
There is a fair amount of prep for the activity since you need to set up an overhead camera with a remote so you can take pictures, and use glow-in-the dark tape to mark out boundaries. You also will need a projector and computer to show the pictures in sequence. The pictures help with closure because they show the inability to predict the location of the particle.
You need to allow about 15-20 minutes for the activity.
There is a fair amount of prep for the activity since you need to set up an overhead camera with a remote so you can take pictures, and use glow-in-the dark tape to mark out boundaries. You also will need a projector and computer to show the pictures in sequence. The pictures help with closure because they show the inability to predict the location of the particle.
Description and Teaching Materials
Probability Activity
Prerequisite Knowledge: Wave/Particle duality, Planck's constant, de Broglie wavelength
1) pick a student to be the particle (m)
2) the class will form a box of a predetermined size (L)
3) There will be a rectangular space on the floor marked out in glow-in-the-dark tape that the "particle" will not be allowed to be "found" in when measured
a) this is where I can tie in wave/particle duality & wave packets
4) the student will then walk to a cadence such that they are moving at a specific speed (v)
5) calculate a student's quantum number
6) rig a camera overhead with a flash that can take a picture of the "box" with the "particle" in it.
7) shut off the lights and have the "particle" move to the cadence
8) take pictures at a predetermined time interval representing where the "particle" is in the box at any particular time
9) to show how quantum size correlates with the quantum world we will make the box smaller and repeat the process eventually getting down to a size where the "particle" is bouncing off the walls of the "box" representing a particle in the quantized world
Prerequisite Knowledge: Wave/Particle duality, Planck's constant, de Broglie wavelength
1) pick a student to be the particle (m)
2) the class will form a box of a predetermined size (L)
3) There will be a rectangular space on the floor marked out in glow-in-the-dark tape that the "particle" will not be allowed to be "found" in when measured
a) this is where I can tie in wave/particle duality & wave packets
4) the student will then walk to a cadence such that they are moving at a specific speed (v)
5) calculate a student's quantum number
6) rig a camera overhead with a flash that can take a picture of the "box" with the "particle" in it.
7) shut off the lights and have the "particle" move to the cadence
8) take pictures at a predetermined time interval representing where the "particle" is in the box at any particular time
9) to show how quantum size correlates with the quantum world we will make the box smaller and repeat the process eventually getting down to a size where the "particle" is bouncing off the walls of the "box" representing a particle in the quantized world
Teaching Notes and Tips
I have not done this in my class yet but I surmise the following areas may pose problems:
o Wave v particle attributes
o Concept of superposition
o Why we can't know exactly where a quantum particle is precisely
o Larger mass = smaller wavelength
o Wave v particle attributes
o Concept of superposition
o Why we can't know exactly where a quantum particle is precisely
o Larger mass = smaller wavelength
Assessment
They will have to complete the following homework assignment for the next day:
1) What evidence can you cite for the wave nature of light? For the particle nature of light?
2) Electrons in electron beam one have a speed of 1000m/s and electrons in beam two have a speed of 10000m/s. Which electrons have a longer de Broglie wavelength? Explain your answer.
3) The equation E=hf describes the energy of each photon in a beam of light. If Planck's constant, h, were larger, would photons of light of the same frequency be more or less energetic? Explain your answer.
4) Calculate the wavelength of an electron, a mouse, and the moon.
1) What evidence can you cite for the wave nature of light? For the particle nature of light?
2) Electrons in electron beam one have a speed of 1000m/s and electrons in beam two have a speed of 10000m/s. Which electrons have a longer de Broglie wavelength? Explain your answer.
3) The equation E=hf describes the energy of each photon in a beam of light. If Planck's constant, h, were larger, would photons of light of the same frequency be more or less energetic? Explain your answer.
4) Calculate the wavelength of an electron, a mouse, and the moon.
Standards
9-12 II.A.7 The student will compare and contrast the states of matter in terms of interactions between particles.
9-12 II.D.8 The student will use Newton's three laws of motion to qualitatively and quantitatively describe the interaction of objects.
9-12 II.D.8 The student will use Newton's three laws of motion to qualitatively and quantitatively describe the interaction of objects.