Particles And Waves Flashcards

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1
Q

Antiparticles

A

For every particle there is another particle known as an antiparticle
The antiparticle has the same mass but a range of opposite effects
Antiparticles join together in the same way particles join to form matter

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2
Q

Posetron

A

(Positive electron)

The antiparticle to a negative electron

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3
Q

Negative anti-proton

A

The antiparticle to a positive proton

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4
Q

What do we call the 12 fundamental particles

A

Fermions

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5
Q

What two groups can fermions be split into

A

Quarks and leptons

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6
Q

Along with quarks and leptons there are 4

A

Bosons

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7
Q

Name the 1st generation quarks

A

Up quark

Down quark

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8
Q

Name the 2nd generation quarks

A

Charm quark

Strange quark

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9
Q

Name the 3rd generation quarks

A

Top quark

Bottom quark

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10
Q

Name the 1st generation leptons

A

Electron neutrino

Electron

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11
Q

Name the 2nd generation leptons

A

Muon neutrino

Muon

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12
Q

Name the 3rd generation leptons

A

Tau neutrino

Tau

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13
Q

Which fermions have a charge of 2/3

A

Up quark
Charm quark
Top quark

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14
Q

Which fermions have a charge of -1/3

A

Down quark
Strange quark
Bottom quark

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15
Q

Which fermions have a charge of 0

A

Electron neutrino
Muo neutrino
Tau neutrino

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16
Q

Which fermions have a charge of -1

A

Electron
Muon
Tau

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17
Q

Name the 4 bosons

A

Photon
Gluon
Z boson
W boson

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18
Q

What is a hadron

A

A particle made of quarks

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19
Q

Baryons

A

Made up of three quarks

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20
Q

Mesons

A

Made of a quark and an anti quark

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21
Q

Give two examples of baryons

A

Proton (UUD)

neuron (UDD)

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22
Q

Mesons

A

Made of a quark and antiquark pair

Because of this they are very unstable

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23
Q

Give an example of a meson

A

A pion is made of an up quark and a down anti-quark and is positively charged

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24
Q

Lepton

A

Fundamental particle (ie can’t be split into smaller particles)

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25
Q

Neutrons

A

Have no charge as they have never interacted with other particles
Produced in a variety of iterations, especially in particle decay
Initially discovered in radioactive beta decay

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26
Q

Beta decay

A

A neutron decays into a proton and electron
In order for momentum to be conserved another particle must be emitted
This is a tau anti-neutrino

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27
Q

the universe contains not only matter but…

A

forces

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28
Q

what causes action (forces) to take place

A

it is thought that attraction or repulsion acts by exchanging particles

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29
Q

exchange particles are called…

A

Bosons

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30
Q

pauli’s exclusion principle

A

two or more identical fermions (particles with half-integer spin) cannot occupy the same quantum state within a quantum system simultaneously (bosons do not follow this)

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31
Q

what is the exchange particle of a strong force

A

gluon

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32
Q

what is the exchange particle of electromagnetic exchange

A

photon

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33
Q

what is the exchange particle of a weak force

A

w and z

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34
Q

what is the exchange particle of gravitational exchange

A

graviton

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35
Q

describe a gluon

A

holds quarks together in baryons and mesons, acts between them

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36
Q

describe a photon

A

a particle like wave, holds electrons in atoms

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37
Q

w+, w- and z*

A

acts on quarks and leptons. involved in beta decay

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38
Q

describe the effects and limits of gravity

A

its affected by gravitons (yet to be discovered), it acts on everything, and its range has no limit

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39
Q

describe the effects and limits of weak electromagnetic forces

A

its affected by w+, w- and z* , it acts on quarts and leptons, and its range is 10^-17m but when affected by photons it acts on quarts and charged leptons and w+, w- and its range has no limit

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40
Q

describe the effects and limits of strong forces

A

its affected by gluons, it acts on quarts and gluons, and its range is 1x10^-15m

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41
Q

describe the Higgs field

A

effects different particles in different ways, photons can slide through unaffected while w and z bosons get bogged down by mass. assuming that it exists everything that has mass does so by passing through the all powerful higgs field.

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42
Q

Higgs Boson

A

like other field in the standard model, the higgs field would need a carrier particle to affect other particles , this is the higgs boson

43
Q

name four sources of uncertainties

A

calibration uncertainty
reading uncertainty
random uncertainty
systematic effects

44
Q

calibration uncertainty

A

when using measuring instruments there will always be error for example when using a meter stick: +/- 0.5mm
this means any reading is only accurate within +/- o.5mm

45
Q

scale reading uncertainty

A

gives an estimate of how accurately a scale can be read

e.g analogue scale = +/- 1/2 smallest division
digital scale= +/- smallest division

46
Q

random uncertainty

A

to give an estimate of how much our repeated values have deviated from the mean values

47
Q

systematic effects

A

often caused by a fault in the measuring implement, or a problem with the method used.

48
Q

Electron feild

A

The region around an electron change

49
Q

In an electric field, an electric charge experiences a

A

Force

50
Q

Electric field strength

A

A measure of the force on a unit charge

51
Q

Work done =

A

QV

52
Q

When a charged is moved between two points in an electric field….

A

Work is done

53
Q

The charge of an object is measured in

A

coulombs

54
Q

Magnetic fields exist around…

A

Moving charges

55
Q

The force exerted on a charge is always…to the velocity of the charge

A

Perpendicular

56
Q

The force exerted on a charge changes the velocity and so…

A

The direction of the applied force as a result

This results in circular motion

57
Q

What are the three main types of particle accelerators

A

Linear accelerators
Cyclotrons
Synchrotrons

58
Q

Name some basic parts of a particle accelerator

A
A source of particles
Beam pipes (vacuum chambers)
Accelerating structures
A system of magnets
A target
59
Q

Describe a source of particles in a particle accelerator

A

May come from accelerator
Accelerators using electrons use thermionic emission
At CERN the source is a bottle of hydrogen gas. The electrons are stripped leaving positively charged protons

60
Q

Describe a beam pipe in a particle accelerator

A

Special pipes in which the particles travel through while being accelerated
The vacuum inside the pipes ensures that the beam particles do not collide with other atoms such as air molecules

61
Q

Describe accelerating structures in a particle accelerator

A

Particles enter a special area where there is a rapidly changing electric field
As protons approach the field is negative and protons accelerate. As they move aaa the field becomes positive and the protons are repelled

62
Q

Describe a system of magnets in a particle accelerator

A

Particles in beam pipes would go in a straight line if they were not constantly going past powerful fixed magnets.
The magnets work best at absolute 0

63
Q

Describe a target in a particle accelerator

A

In some accelerators the beam collided directly with a stationary target, such as a metal block
In the LHC the target is a bunch of particles travelling in opposite directions

64
Q

Radioactive decay

A

The breakdown of a nucleus to release energy and matter from the nucleus
This allows stability to be achived

65
Q

Radioisotopes (radionuclides)

A

Unstable nuclei

66
Q

Alpha particles

A

4/2He

Helium nucleus

67
Q

Beta particle

A

0/-1e

Fast electron

68
Q

Gamma ray

A

High frequency electromagnetic wave

69
Q

Describe alpha decay

A

Occurs in heavy nuclei (uranium, plutonium)
Major part of radioactive fallout
Relatively more massive so less penetrating
If an alpha decaying element in ingested it can do considerable damage

70
Q

Describe beta decay

A

Occurs when an atom has too many protons or neutrons in its nucleus
Positive beta decay releases a positron and neutrino
Negative beta decay releases an electron and anti neutrino
These are high energy elementary particles released in order to conserve energy

71
Q

Describe gamma decay

A

Results from the registration of electric charge within a nucleus
Essentially very energetic x-rays but instead of being emitted during atomic processes involving energetic electrons gamma radiation is emitted by excited nuclei or other processes involving sub atomic particles
More penetrating but less ionising
Produce burns, cancer and genetic mutations

72
Q

Nuclear fission

A

When a heavy nucleus disintegrates , forming two nucleus of smaller mass number
It can be spontaneous or induced by neutron bombardment

73
Q

Why is energy released in nuclear fission

A

Mass is a form of energy , when there is a decrease in mass an equivalent amount of energy is produced
This can be calculated by E=Mc^2

74
Q

Nuclear fusion

A

Nuclear energy is also released by the fusion of two light elements
There is no limit to the amount of fusion that an occur
Very high temperatures are needed

75
Q

To sustain fusion the conditions that must be met are;

A

Extremely high temperatures (T): 100-200 million K
A stable reaction lasting 5 seconds (energy confinement time (t))
A precise plasma density of around 10^20 particles/ m3

76
Q

Name the main parts of a nuclear fission reactor

A
Fuel rods
Moderator 
Control rods
Coolant
Containment vessel
77
Q

Describe fuel rods in a fusion reactor

A

Pellets of enriched uranium are stacked in a rod, the mass below critical mass and the rods are grouped to form elements

78
Q

Describe a moderator in a fusion reactor

A

Graphite water or heavy water surrounds the uranium elements so neutrons passing between elements can be slowed by collision

79
Q

Describe control rods in a fusion reactor

A

Made of boron
Can be lowered or raised between the fuel rods to absorb neutrons
They are lowered to reduce the chain reaction or raised to meet the demand

80
Q

Describe coolant in a fusion reactor

A

Removes heat
A pressurised liquid or gas such as water or carbon dioxide
Energy is passed through a heat exchanger to a turbine and electrical generator

81
Q

Describe a containment vessel in a fusion reactor

A

The reactor is surrounded by a large steel lining and concrete to absorb radiation in an accident or in the event of natural disaster

82
Q

Photoelectric effect

A

Under certain circumstances an electrically charged object can be made to discharge by shining electromagnetic radiation at it
Only if it is negatively charged and the radiation is of a sufficiently high frequency

83
Q

Wave particle duality

A

Light can act as both a wave and a particle

84
Q

E=hf

A

E= energy of photon (J)
f= frequency of photon (Hz)
h=Planks constant (6.63x10^-34 Js)

85
Q

The thread hold frequency (f°) for each metal is….

A

Different

86
Q

Increasing the frequency will not increase

A

The number of photo electrons

87
Q

Increasing the frequency will increase

A

The speed at which the photo electrons eject

88
Q

Increase the number of photos will…

A

Increase the number of photo electrons

89
Q

The name given to the small amount of energy required to bring an electron to the surface of a metal and free it is …

A

The work function

90
Q

Work function =

A

E°=hf°

91
Q

Irradiance =

A

P N x hf
__=________=Nhf
A 1

92
Q

What is meant by a wave that is in phase

A

Two points on a wave that are vibrating in exactly the same way at the same time

93
Q

What is meant by a wave that is exactly out of phase

A

Two waves vibrating crest to trough at the same time

94
Q

Coherent sources

A

Two sources that are oscillating with a constant phase relationship
Have the same frequency

95
Q

When two coherent waves in phase meet….

A

Constructive interference occurs

96
Q

When two coherent waves out of phase meet..

A

Destructive interference occurs

97
Q

Interference is evidence for….

A

The wave model of light

98
Q

Constructive interference occurs when…

A

Path difference= mλ

99
Q

Destructive interference occurs when

A

Path difference= (m+1/2)λ

100
Q

Continuous spectra

A

All frequencies of radiation are present in the spectrum. The continuous spectrum colours are red, orange, yellow, green, blue, indigo, violet

101
Q

Line emission spectra

A

Emitted by excited atoms in a low pressure gas. Each element emits it’s own unique line spectrum
Lines on emission spectrum made by electrons making the transition from high energy levels to low energy levels. When an excited electron drops it releases a photon of a specific frequency that corresponds to a line on the spectrum

102
Q

Absorbtion spectra

A

Energy absorbed from electrons is emitted as a photon of the same energy and frequency as the one absorbed, but it is unlikely to be emitted in the same direction. Therefore the spectrum will show black absorbtion lines

103
Q

Farenhofer lines

A

The absorbtion lines in the absorbtion spectra of sunlight