Chapter 1 - Matter and Radiation

Question 1

What is a nucleon?

Answer 1

A neutron or proton in the nucleus

Question 2

What is the atomic number?

Answer 2

Number of protons in the nucleus

Question 3

What is an isotope?

Answer 3

Atoms of the same element with the same number of protons but different numbers of neutrons

Question 4

What is the nucleon number?

Answer 4

The number of neutrons and protons in the nucleus

Question 5

What is the relative charge of a proton?

Answer 5

+1

Question 6

What is the relative charge of an electron?

Answer 6

-1

Question 7

Equation for specific charge

Answer 7

Specific charge = charge ÷ mass

Question 8

What is the strong nuclear force?

Answer 8

The force that keeps neutrons and protons together in the nucleus

Question 9

What is the range of the strong nuclear force?

Answer 9

It is attractive from 4 fm to 0.5 fm, and then is repulsive

Question 10

What is specific charge?

Answer 10

Definition = charge ÷ mass
Electrons have the highest specific charge of any particle (given in equations booklet)
An atom has no charge

Question 11

What is an alpha particle?

Answer 11

Helium particle / 2 neutrons and 2 protons

Question 12

What is a beta - particle?

Answer 12

An electron

Question 13

What is a beta + particle?

Answer 13

A positron

Question 14

Beta - decay

Answer 14

• Neutron changes into a proton
• An electron and anti electron neutrino are created and emitted

Question 15

Why is the specific charge of an electron larger then that of a hydrogen nucleus?

Answer 15

The specific charge of an electron is about 2000 x higher because it’s mass is so much smaller. The hydrogen nucleus and an electron have the same charge, but hydrogen’s mass is about 2000 times bigger.

Question 16

Beta + decay

Answer 16

• A proton changes into a neutron
• A position and an electron neutrino are created and emitted

Question 17

Neutrino

Answer 17

The neutrino’s existence was predicted because energy was not conserved in beta decay

Question 18

1 eV

Answer 18

1.6 x 10 to the power of -19 J (in the booklet)

Question 19

What is a photon?

Answer 19

• A packet of electromagnetic radiation
• The “smallest piece”
• Zero mass
• Zero charge
• Their energy is proportional to their frequency

Question 20

Equation for energy of a photon

Answer 20

E=hf
Plank’s constant x frequency

Question 21

Wavespeed

Answer 21

Frequency x wavelength

Question 22

What is antimatter?

Answer 22

• Every particle has an equivalent antiparticle
• an antiparticle is like the mirror image of the respective particle

Antimatter has opposite charge and the same mass as the matter equivalent

Question 23

What are the antiparticles?

Answer 23

Proton (p) | antiproton (p_)
Neutron (n) | antineutron (n_)
Electron (e) | positron (e+)
Electron neutrino (Ve) | anti electron neutrino (Ve_)

Question 24

Beta decay equations

Answer 24

Beta - = n -> p + e + Ve_
Beta + = p -> n + (e+) + Ve

Question 25

What is annihilation?

Answer 25

- Matter and antimatter destroy each other, or annihilate, whenever they come into contact - Matter then turns into energy -> E = m x c2 - The matter and antimatter then mutually destructs in a "puff" of light consisting of two photons sent out in precisely opposite directions, each with an energy corresponding exactly to the mass of the matter - 2 photons are produced in opposite directions to conserve momentum

Question 26

What is the rest mass?

Answer 26

The rest energy, which is the energy needed to create the particle

Question 27

What is pair production?

Answer 27

- The opposite of annihilation - Photons producing a particle and its corresponding antiparticle - Usually happens in the presence of a nucleus to conserve momentum - Usually an electron and position as they are the lowest mass Look on good notes for diagram

Question 28

Particle interactions

Answer 28

Particle interactions (forces) are caused by exchange particles (bosons, sometimes called message particles)

Question 29

What are the 4 fundamental particle interactions?

Answer 29

Gravity Electromagnetic Weak nuclear Strong nuclear

Question 30

How do matter particles interact?

Answer 30

An exchange particle is exchanged between the particles They are called virtual photons as they only exist for very short periods of time

Question 31

What is the exchange particle for electromagnetic interaction?

Answer 31

Virtual photon

Question 32

Weak nuclear force

Answer 32

Responsible for subatomic particle decays like beta - and + The exchange particles are w- and w+

Question 33

What is rest energy?

Answer 33

The energy equivalence of the particles mass