Antiparticles And Photons

Question 0

What is the electromagnetic spectrum?

Answer 0

A continuous spectrum of all the possible frequencies of electromagnetic radiation.

Question 1

What type of light is electromagnetic radiation?

Answer 1

Visible light.

Question 2

Define “frequency”.

Answer 2

The number of complete waves passing a point per second.

Question 3

Define “wavelength”.

Answer 3

The distance between two adjacent crests of a wave.

Question 4

What are photons?

Answer 4

Photons are “wave-packets” that EM waves exist in.

Question 5

What is the equation used to calculate the energy carried by one photon?

Answer 5

Energy of one photon = plancks constant x frequency of light

Question 6

What is the equation that relates frequency, wavelength and speed of light?

Answer 6

Frequency = (speed of light)/wavelength

Question 7

What are the units of the following:
A) energy
B) frequency
C) Planck's constant
D) speed of light
E) wavelength

Answer 7

A) joules
B) hertz
C) Joules seconds
D) metres per second
E) metres

Question 8

State the relative charge of a proton and it’s antiparticle?

Answer 8

Proton: +1
Antiproton: -1

Question 9

State the relative charge of a neutron and it’s antiparticle.

Answer 9

Neutron: 0
Antineutron: 0

Question 10

State the relative charge of an electron and it’s antiparticle.

Answer 10

Electron: -1
Positron: +1

Question 11

State the relative charge of an electron neutrino and it’s antiparticle.

Answer 11

Electron neutrino: 0

Electron anti-neutrino: 0

Question 12

What is pair production?

Answer 12

A process of converting energy to mass in which a gamma ray photon has enough energy to produce a particle-antiparticle pair.

Question 13

Why must pair production always produce a particle AND it’s corresponding anti-particle?

Answer 13

Certain quantities must be conserved.

Question 14

What equation is used to calculate the minimum energy needed for pair production?

Answer 14

Minimum energy = 2 x rest energy of particle type

Question 15

What is annihilation?

Answer 15

Annihilation is the result of a particle meeting it’s antiparticle.

Question 16

What is the result of annihilation?

Answer 16

All the mass of the particle and antiparticle gets converted back to energy in the form of two gamma ray photons.

Question 17

Why do antiparticles not exist in ordinary matter?

Answer 17

They can only exist for a fraction of a second before annihilation.

Question 18

What equation is used to calculate the minimum energy of a photon produced by annihilation?

Answer 18

Minimum energy = rest energy of particle type annihilated