(2.1) - Particles and Radiation

Question 1

(2.1.1) What do each letter stand for

AZX Notation:

Answer 1

A: Nucleon Number
Z: Proton Number
X: Chemical Symbol

Question 2

How to calculate specific charge of nuclei

Answer 2

• SC = Total Charge / Total Mass
• Total charge = number of protons X 1.6 X 10^-19
• Total Mass = (number of protons X rest mass of proton) + (number of neutrons X rest mass of neutron)

Question 3

How to calculate specific charge of ion

Answer 3

• SC = Total charge / Total Mass
• Total charge = 0 - Number of electrons gained
• Total Mass = (number of protons X rest mass of proton) + (number of neutrons X rest mass of neutron)

Question 4

Isotope definition

Answer 4

• Atoms of same element with same number of protons and electrons but different number of neutrons

Question 5

(2.1.2)

What is the Strong Nuclear Force (SNF)

Answer 5

• The force keeping protons and neutrons together

Question 6

Repulsion range in SNF

Answer 6

0 - 0.5 fm

Question 7

Attraction range in SNF

Answer 7

0.5 - 3 fm

Question 8

Alpha decay

Answer 8

• Nucleus emmiting 2 protons and 2 neutrons

Question 9

Beta - Decay

Answer 9

n -> p + β- + ̅νe

Question 10

Beta + Decay

Answer 10

p -> n + β+ + νe

Question 11

Annihilation

Answer 11

When a particle meets its corresponding antiparticle they are both destroyed and their mass is converted into energy in the form of two gamma-ray photons

Question 12

Explain how the existance of the neutrino was hypothesised

Answer 12

• In B- decay, electrons had a range of energies, not one fixed energy
• This means there was missing energy, so it was hypothesised that there was another particle carrying the remained energy

Question 13

How does a particle and antiparticle’s masses, charge and rest energy (MeV) compare?

Answer 13

• Same masses and rest energy, but opposite charge

Question 14

What is a photon

Answer 14

• Massless quantum of EM energy

Question 15

Pair Production

Answer 15

When a photon interacts with a nucleus or atom and the energy of the photon is used to create a particle–antiparticle pair

Question 16

Four fundamental interactions:

Answer 16

• Strong
• Weak
• Gravitational
• Electromagnetic

Question 17

Exchange Particle for SNF

Answer 17

Pion

Question 18

Exchange particle for Weak interaction

Answer 18

W boson (W+ or W-)

Question 19

Exchange particle for Electromagnetic interaction

Answer 19

Virtual photon

Question 20

The weak interaction occurs in —

Answer 20

• β decay
• Electron capture
• Electron-proton collision

Question 21

Hadrons are subject to the … interaction

Answer 21

Strong

Question 22

The two classes of hadrons:

Answer 22

• baryons (proton, neutron) and antibaryons
  (antiproton and antineutron)
• mesons (pion, kaon) and antimesons (antipions and antikaon)

Question 23

All quantum numbers:

Answer 23

• Baryon
• Lepton
• Strange
• Charge

Question 24

What is the only stable baryon

Answer 24

proton

Question 25

What particles are subject to conservation

Answer 25

* Lepton * Charge * Baryon

Question 26

What do kaons decay into

Answer 26

Pions

Question 27

What are the different kind of Leptons

Answer 27

* Electron * Muon * Neutrino

Question 28

What does a muon decay into

Answer 28

Electron

Question 29

How are strange particles produced and how do they decay

Answer 29

* Produced in strong interaction * Decays in weak interaction

Question 30

Explain conservation of strangeness in all interactions

Answer 30

* Strong, EM and Gravitational : fully conserved * Weak : Can change by -1, 0, and 1

Question 31

Why do particle physics relies on the collaborative efforts of large teams of scientists and engineers

Answer 31

* High cost * Validate new knowledge * Ensures accuracy across different teams

Question 32

Properties of quarks and antiquarks

Answer 32

* Charge * Baryon number * Strange number

Question 33

Combination of quarks required for Proton and Neutrons (Baryons)

Answer 33

* Proton: UUD * Neutron: UDD

Question 34

Combination of quarks required for Pions

Answer 34

π: * + = udˉ * - = duˉ * ⁰ = uuˉ and 𝑑𝑑ˉ

Question 35

Combination of quarks required for Kaons

Answer 35

K: * + = 𝑢𝑠ˉ * - = 𝑠𝑢ˉ * ⁰ = 𝑑𝑠ˉ * K̅⁰ = sdˉ

Question 36

3 flavours of quarks

Answer 36

* Up * Down * Strange

Question 37

When is strange number conserved

Answer 37

Every interaction except weak in a range of -1, 0 or 1

Question 38

1. Types of Leptons 2. Define them

Answer 38

1. Muon, a heavier electron 2. Electron 3. Neutrino, a nearly mass less particle

Question 39

Types of mesons

Answer 39

* Pion (SNF exhange particle) * Kaon (Strange particle, decays into pions)

Question 40

Quark character change in b- and b+ decay

Answer 40

b- neutron: neutron (udd) to proton (uud) b+ is opposite

Question 41

In which interactions are quantities conserved

Answer 41

All except weak, where strangeness is not conserved