Particles Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are the main constituents of the atom?

A

*Proton
*Neutron
*Electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define specific charge

A

Specific charge = charge / mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Specific charge of a proton?

A

Charge = 1.6x10^-19
Mass 1.67x10^-27

1.6x10^19/1.67x106-27 = 9.58x10^7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the letter associated with proton number?

A

Z

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a nucleon?

A

A constituent of the nucleus : a proton or neutron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What letter represents nucleon number?

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which is correct: AXZ or ZXA?

A

AZX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an isotope?

A

Two elements that have the same amount of protons but a different amount of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

State a use of radioactive isotopes

A

*Carbon dating - The proportion of carbon-14 in a material can be used to determine its age
*Cancer detection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a strong nuclear force?

A

The fundamental force that keeps the nucleus stable by counteracting the electrostatic force of repulsion between protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe range of strong force

A

*Repulsive up to 0.5fm
*Attractive from 0.5-3fm
*Negligible past 3fm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What makes a nucleus unstable?

A

Nuclei that have far too many protons, neutrons or both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do nuclei with too many nucleons decay?

A

Alpha decay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do nuclei with too many neutrons decay?

A

Beta minus decay (udd to uud)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is the existence of a neutrino hypothesised?

A

The energy of particles after beta decay was lower than before, a particle with 0 charge and negligible mass must carry away this excess energy, this particle is a neutrino

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is meant by beta minus decay?

A

When a neutron turns into a proton, the atom releases an electron and an anti-electron neutrino

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is an alpha particle?

A

A particle that contains two protons and two neutrons

18
Q

What is an antiparticle?

A

For each particle there is an antiparticle with the same rest energy and mass but all other properties are the opposite of its respective particle

19
Q

Antiparticle of an electron

A

Positron

20
Q

Antiparticle of Pi0

A

Pi0

21
Q

What occurs when a particle and antiparticle meet?

A

Annihilation :
The mass of the particle and antiparticle is converted back to energy in the form of 2 gamma ray photos which go in opposite directions to conserve momentum

22
Q

Pair production definition

A

A gamma ray photon is converted to a particle-antiparticle pair

23
Q

Min energy of a photon required to make a proton-antiproton pair

A

2 x proton rest energy
2 x 9.38.257 = 1876.514 MeV

24
Q

4 Fundamental forces

A

*Gravity
*Electromagnetic
*Weak nuclear
*Strong nuclear

25
Q

The virtual photon is the exchange particle of which force?

A

The electromagnetic force

26
Q

What type of particle is affected by the strong force?

A

Hadrons

27
Q

What is the exchange particle of the weak nuclear force?

A

W boson (W- or W+)

28
Q

What does the electromagnetic force act?

A

It acts on all charged objects, for example when a positively charged ball repels another positively charged ball

29
Q

When does weak nuclear interaction occur?

A

When a quark changes, it affects all types of particles

30
Q

What property must be conserved in particle interactions?

A

*Energy
*Charge
*Baryon number
*Lepton number
*Momentum
*Strangeness

31
Q

What is a hadron

A

Both baryons and mesons are hadrons, made up of at least 2 quarks and interact via strong nuclear force

32
Q

Classes of hadrons

A

*Baryons - qqq
*Mesons - quark antiquark

33
Q

Pion and kaon are both examples of which class of particles?

A

Mesons

34
Q

The pion can be a exchange particle for which force?

A

Strong nuclear force

35
Q

What particle does a kaon decay into?

A

A kaon decays into a pion

36
Q

Example of baryons

A

*Proton - uud
*Neutron - ddu

37
Q

What is significant about a proton?

A

*The only stable baryon
*All baryons will decay into protons

38
Q

Examples of leptons

A

*Muon
*Electron
*Neutrino

39
Q

Examples of leptons

A

*Muon
*Electron
*Neutrino

40
Q

What does a muon decay into?

A

An electron

41
Q

What is the strangeness value of a strange quark?

A

-1