Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A level physics > CGP AS Section 1 - Particles > Flashcards

CGP AS Section 1 - Particles Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What are atoms made up of?

A

Protons
Neutrons
Electrons

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

Where are the constituents of an atom located?

A
  • protons and neutrons in the nucleus

- electrons orbiting the nucleon core

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

What are nucleons?

A

protons and neutrons

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

What is the relative charge and mass of a proton?

A

relative charge: +1

relative mass: 1

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

What is the relative charge and mass of a neutron?

A

relative charge: 0

relative mass: 1

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

What is the relative charge and mass of a electron?

A

relative charge: -1

relative mass: 1/2000

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

What is the proton number?

A

The proton number is the number of protons in the nucleus of an atom
-it defines the element, no two elements will have the same one

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

What does the proton number of an atom tell you?

A
  • the number of electrons in a neutral atom

- so it tells you a lot about its chemical properties cause electrons determine the chemical behaviour of an atom

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

What is the nucleon number?

A

the total number of protons and neutrons

-the number of nucleons is the same as the atom’s relative mass

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

What is the symbol of the proton number?

A

Z

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

What is the symbol of the nucleon/mass number?

A

A

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

Define ion:

A

A particle with a different number of electrons to protons

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

Define isotope:

A

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

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

What does changing the number of neutrons in an atom do?

A
  • doesn’t affect its chemical properties

- affects the physical properties (e.g. the stability of the nucleus, unstable nuclei may be radioactive and decay)`

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

What can radioactive isotopes be useful for?

A

To see how old stuff is

  • all living things contain the same percentage of carbon-14 taken in from the atmosphere
  • after they die this amount decreases as carbon-14 decays into stable elements
  • scientist can use this to calculate an approximate age of dead organic matter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What type of data do scientists use to calculate the approximate age of dead organic matter?

A 
ISOTOPIC DATA (amount of each isotope that is present)
-to find the percentage of radioactive carbon-14 that is left in an object
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the specific charge of a particle the same as?

A

its charge over its mass

specific charge = charge ÷ mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the unit for specific charge?

A

C kg⁻¹

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a fundamental particle?

A

A fundamental particle is one that you can’t break up into anything smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the forces acting on the nucleons in a nucleus?

A
  • electrostatic forces
  • gravitational forces
  • strong force
  • weak force
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are some features of the strong force?

A
  • it is an attractive force stronger then the electrostatic force
  • very short range (fm range)
  • strength quickly falls from 3fm to being neutral at 5fm
  • works equally between all nucleons (for protons and neutrons)
  • below 0.5fm it is repulsive to stop the nucleons crushing to a point
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why do alpha emissions occur?

A

-occur in very big nuclei (e.g. uranium and radium), so they are too big for the strong force to keep them stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is an alpha emission?

A

a helium nucleus (two protons and two neutrons)

  • proton number decreases by two
  • nucleon number decreases by four
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the features of alpha particles?

A
  • have a very short range (only a few centimeters in air), this can be observed by seeing alpha particle tracks in a cloud chamber
  • Geiger counter can also show the short range as the count rate drops of rapidly with a little distance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is a beta-minus emission?

A

the emission of an electron and an antineutrino

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Why does beta decay occur?

A

it happens in isotopes that are unstable due to being ‘neutron rich’ (having too many more neutrons than protons in their nucleus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens during beta decay?

A

One of the neutrons is changed into a proton

-so the proton number increases by one and the nucleon number stays the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does the antineutrino carry when it’s released in beta-minus decay?

A

some energy and momentum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How were neutrinos hypothesized?

A
  • observations of beta decay showed there was less energy after than before (which doesn’t fit the conservation of energy law)
  • Pauli suggested another particle was being emitted too, it had to be neutral (to conserve charge) and had to have zero or almost zero mass (as it had never been detected)
  • neutrinos were then observed 25 years later providing evidence for the hypothesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the electromagnetic spectrum?

A 
radio waves
microwaves
infrared 
visible light
ultra violet
x-rays
gamma rays
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What happens the frequency and wavelength when you go from radio waves to gamma rays on the electromagnetic spectrum?

A
  • frequency increases

- wavelength decreases

32
Q

What is the equation linking frequency and wavelength and the speed of light?

A

frequency = speed of light ÷ wavelength

33
Q

What does the energy of a photon depend on?

A

the frequency of the radiation

-electromagnetic radiation exists as photons of energy

34
Q

What is the difference between a particle and its antiparticle?

A

-opposite charge

35
Q

What are the similarities between a particle and its antiparticle?

A

-has same mass and same rest energy

36
Q

What is the relative charge and symbol of a proton?

A

symbol: p

relative charge: +1

37
Q

What is the relative charge and symbol of a antiproton?

A

symbol: p with a bar above it

relative charge: -1

38
Q

What is the relative charge and symbol of a neutron?

A

symbol: n

relative charge: 0

39
Q

What is the relative charge and symbol of a antineutron?

A

symbol: n with a bar above it

relative charge: 0

40
Q

What is the relative charge and symbol of a electron?

A

symbol: e⁻

relative charge: -1

41
Q

What is the relative charge and symbol of a positron?

A

symbol: e⁺

relative charge: +1

42
Q

What is the relative charge, mass and symbol of a neutrino?

A

symbol: ν (a slanted v with a subscript letter according to the type of neutrino)
relative charge: 0
mass: 0

43
Q

What is the relative charge, mass and symbol of a proton?

A

symbol: ̅ν (a slanted v with a bar and a subscript letter according to the type of neutrino)
relative charge: 0
mass: 0

44
Q

What can you create antimatter and matter from and why?

A

antimatter and matter can be created from energy
-this comes from Einstein’s special theory of relativity, the rest energy of a particle is just the energy equivalent of its mass (comes from E = mc²)

45
Q

What happens when energy is converted into mass?

A

You get equal amounts of matter and antimatter

46
Q

What is pair production?

A

When two particles are fired at each other at a high speed, there will be a lot of energy at the point of impact, this energy might be converted to more particles (each in matter and antimatter pairs)

47
Q

When will pair production occur?

A

if one photon has enough energy to produce that mass, only gamma ray photons have enough energy
-tends to happen near to a nucleus which helps to conserve momentum

48
Q

What is a photon?

A

energy that gets converted into matter and antimatter is in the form of photon

49
Q

What is the most common pair produced by pair production and how does it travel once it is produced?

A
  • electron-positron pair is the most common (because they have a relatively low mass)
  • the particles travel in curved paths as there’s usually a magnetic field present, and in opposite direction as they are oppositely charged
50
Q

What is the minimum energy required for a photon to undergo pair production?

A

the total rest energy of the particles produced

51
Q

What is the opposite of pair production?

A

annihilation

52
Q

What is annihilation?

A

When a particle meets its antiparticle and all the mass gets converted back into energy (photons)

53
Q

During annihilation what happens to the energy?

A

-both photons produced need to have a minimum energy, which when added together equals at least the rest energy of the particles involved added together (for energy to be conserved)

54
Q

What force interactions are explained by exchange particles?

A

REPULSION
ATTRACTION
-when two particles interact either of these happen to let one particle know the other is there

55
Q

What is another name for an exchange particle?

A

gauge boson

56
Q

What are the four fundamental forces which cause all forces in nature?

A

electromagnetic force
gravity
weak nuclear force
strong nuclear force

57
Q

What is the gauge boson for an electromagnetic interaction and what particles does it affect?

A

Gauge boson: virtual photon

Particles affected: charged particles only

58
Q

What is the gauge boson for a weak nuclear force interaction and what particles does it affect?

A

Gauge boson: W⁺ and W⁻

Particles affected: all types

59
Q

What is the gauge boson for a strong nuclear force interaction and what particles does it affect?

A

Gauge boson: pions ( π⁺ and π⁻ and π⁰)

Particles affected: hadrons only

60
Q

Why do particle physicists not bother about gravity?

A
  • it is feeble in comarison to other interactions

- gravity only really matters when you have big massess

61
Q

What are the two types of gauge bosons for strong force and what are their jobs?

A

PIONS - exchanges between nucleons

GLUONS - exchanges between quarks

62
Q

What is the relationship between the mass of a gauge boson and the range of the force?

A

larger mass causes a shorter range

  • W bosons have about 100 times the mass of a proton and so have a very short range
  • a virtual photon has zero mass and so it has an infinite range
63
Q

What diagrams can you draw to show particle interactions and what are some general rules?

A

Feynman Diagrams

  • gauge bosons are represented by wiggly lines slanted up and with an arrow showing direction
  • other particles shown by a straight line and arrows
  • incoming particles start at the bottom and move up
  • baryons and leptons are on separate sides
  • charges on both sides need to balance (W bosons can carry charge from one side to the other)
64
Q

Describe a Feynman diagram for electromagnetic repulsion:

A

(can be for electrons or positrons)

  • has a virtual photon as the exchange particle
  • has a lepton line up on either side of the gauge boson squiggle (so 4 lepton lines are labelled)
65
Q

Describe a Feynman diagram for electron capture:

A
  • it is a weak interaction
  • has a proton and electron coming from below then a W⁺ boson with the arrow going from the boson to the lepton side
  • has a neutron and a neutrino coming out from above that
66
Q

Describe a Feynman diagram for electron-proton collisions:

A
  • it is a weak interaction
  • has a proton and electron coming from below then a W⁻ boson with the arrow going from the lepton to the boson side
  • has a neutron and a neutrino coming out from above that
67
Q

Describe a Feynman diagram for Beta-plus decay:

A

n –> p + e⁺ + neutrino

  • has a W⁺ boson for exchange
  • only has a neutron below and then a proton on the boson side and both a positron and a neutrino coming out of the lepton side with nothing below
68
Q

Describe a Feynman diagram for Beta-minus decay:

A

p –> n + e⁻ + antineutrino

  • has a W⁻ boson for exchange
  • only has a proton below and then a neutron on the boson side and both a electron and a antineutrino coming out of the lepton side with nothing below
69
Q

What is the nucleus of an atom made up of?

A

Protons and neutrons

70
Q

What force holds protons together since they are all positively charged and so should repel each other?

A

Strong nuclear force or the strong interaction

71
Q

What particle can and can’t feel the strong nuclear force?

A

can - hardrons

can’t - leptons

72
Q

What particles are fundamental and what aren’t?

A

fundamental - leptons

non-fundamental - hadrons

73
Q

What are hadrons made up of?

A

quarks

74
Q

What are the two types of hadrons?

A
  • baryons and anti-baryons

- mesons

75
Q

What determines which type of hadron a particle is?

A

the number of quarks that make them up

76
Q

What particles are called nucleons?

A

Protons and neutrons

A level physics (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions