Particles Section Flashcards

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1
Q

What is the definition for a potential difference of 1 Volt?

A

There is a potential difference of 1 Volt between two points if I joule of energy is required to move 1 coulomb of charge between the two points.

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2
Q

What force is carried by a photon?

A

Electromagnetic Force

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3
Q

What are the fingers representing in the right hand rule?

A
  1. First Finger - Field (Magnetic field)
  2. SeCond finger - Current
  3. THumb - Thrust (Movement)
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4
Q

Describe the electric field between a positive charge and a negative charge.

A

Field lines run from positive towards negative.

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5
Q

Describe the electric field around a positive charge.

A

Field lines away from the positive charge.

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6
Q

Give an example of a Baryon.

A

Proton

Neutron

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7
Q

What is meant by a Meson?

A

Mesons are made from 2 quarks.

They always consist of a quark and an antiquark pair.

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8
Q

What is a Boson?

A

Bosons are force carrying particles.

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9
Q

In the photoelectric effect, if the frequency of the incident radiation is increased what happens?

A

The electrons ejected will have more kinetic energy, if the frequency is greater than the threshold frequency.

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10
Q

What is beta (minus) decay?

A

Beta (minus) decay is when a neutron decays into a proton releasing an electron and an antineutrino.

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11
Q

Explain how a particle accelerator works.

A
  1. Acceleration of charged particles - use an electric field which causes particles to experience a force and accelerates them.
  2. Deflection of charged particles - magnetic fields are used to chage the direction of the moving charged particles.
  3. Collision of charged particles - against a fixed target or between two beams of particles.
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12
Q

What is the threshold frequency?

A

The minimum frequency of light required to eject an electron from a metal surface.

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13
Q

What represents a magnetic field going ‘into the page’?

A

A cross

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14
Q

What represents a magnetic field coming ‘out of the page’?

A

A dot

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15
Q

Name the four Bosons.

A
  1. Photons
  2. W and Z Bosons
  3. Gluons
  4. Gravitons
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16
Q

In a fusion reactor why are the high temperatures required a problem?

A

High temperature required to give the hydrogen atoms enough energy to overcome the electrical repulsion between the protons. This is difficult to contain as all materials would vaporise at this temperature.

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17
Q

What is meant by a Hadron?

A

Particles made from quarks

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18
Q

What is the Standard Model?

A

The Standard Model explains how the basic building blocks of matter interact, governed by four fundamental forces.

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19
Q

What is a fundamental particle?

A

A fundamental particle is one that cannot be broken down into any sub particles.

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20
Q

What did beta decay provide the first evidence for?

A

The existence of neutrinos.

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21
Q

What is meant by fusion?

A

Fusion is when two small mass number nuclei combine to form a nucleus of a larger mass number.

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22
Q

Why were neutrinos suggested as an extra particle produced as a result of beta decay?

A

When beta decay occurs momentum and energy should be conserved. This was not happening if only the proton and beta particle were considered. There had to be another particle that carried the rest of the energy away.

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23
Q

When will a gold leaf electroscope discharge?

A
  • It must be negatively charged
  • It must have a zinc plate
  • Ultraviolet light of a high enough frequency must be shone on the plate
  • When the frequency of the ultraviolet light is above the threshold frequency
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24
Q

In physics what is meant by a field?

A

It is the region where an object experiences a force.

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25
Q

What evidence is there for antimatter?

A

Positrons discovered ocurring naturally in cosmic rays.

26
Q

What force is carried by a Graviton?

A

Gravity force

27
Q

How does an antimatter particle compare with a matter particle?

A

Antimatter particle has similar properties to the matter particle but equal and opposite charge.

28
Q

What can you say about electrons absorbing photons in the photoelectric effect?

A
  • An electron can only absorb the energy from one photon
  • The electron absorbs all the energy from the photon.
29
Q

In the photoelectric effect, if the irradiance of the incident radiation is increased what will happen?

A
  • No electrons will be ejected if the frequency of the incident radiation is below the threshold frequency.
  • If the frequency is above the threshold frequency then more electrons will be ejected from the surface.
30
Q

Why does the photoelectric effect give evidence for light to be considered as a particle?

A
  • Photoelectric effect cannot be explained if light is thought of as a wave or any light would cause photoemission if it shone on the surface long enough to deliver enough energy to the electrons..
  • Each photon contains a discrete amount of energy which results in one photon ejecting one electron
31
Q

What is meant by a Baryon?

A

Baryons are made from 3 quarks

32
Q

What force is carried by a Gluon?

A

Strong force

33
Q

If an incident photon is greater than the work function what happens to the rest of the photon’s energy?

A

The electron that is ejected has the rest of the energy as kinetic energy.

34
Q

If an unstable nucleus undergoes beta decay what is given out and what is the effect on the mass number and the atomic number?

A

An electron from the nucleus is given out along with an antineutrino.

The mass number of the product remains the same and the atomic number increases by one.

35
Q

What will a stationary charge create?

A

An electric field

36
Q

What is meant by fission?

A

Fission is when a nucleus of a large mass number splits into two or more nuclei of smaller mass numbers.

37
Q

Containment and cooling are issues associated with a nuclear fusion reactor. Why?

A

Temperature of the reaction is so high most materials will vaporise. So a magnetic field can be used to suspend the plasma away from the sides of the container.

This requires strong magnetic fields produced by superconducting coils. These only work at cery low temperatures so need good cooling systems.

38
Q

What is the Work Function?

A

The minimum energy required to eject an electron from a metal surface.

39
Q

What are the two types of Fermions?

A

Quark

and

Lepton

40
Q

What will a moving charge create?

A
  1. An electric field
  2. Magnetic field
41
Q

Describe the field lines between parallel plates.

A

Field lines run from positive to negative plates.

42
Q

Describe the field lines between two negative charges.

A

The field lines run towards the negative charges but no filed lines between them.

43
Q

In the photoelectric effect, what happens to the maximum kinetic energy of an electron if the irradiance is increased?

Why?

A
  • There is no effect on the maximum kinetic energy it remains the same.
  • The energy of the incident photons (E = hf) is unchanged.
44
Q

What is meant by irradiance?

A

The power per unit area

45
Q

What force is carried by W and Z bosons?

A

Weak force

46
Q

What is the definition for electric field strength?

A

The electric force per unit charge acting at a point in the field.

47
Q

Give one advantage of producing electricity by nuclear fusion.

A
  • Abundant fuel supply (Deuterium can be extracted from sea water)
  • Safe (Small amounts of fuel, if reaction is unchecked it results in it stopping)
  • Clean (No combustion so no air pollution)
  • Less nuclear waste (waste is not high level weapons grade, needs stored for about 100 years)
  • Efficient (1kg fusion fuel gives same energy as 10 million kg of fossil fuels)
48
Q

If an unstable nucleus undergoes alpha decay what is given out and what is the effect on the mass number and the atomic number?

A

An alpha particle is a helium nucleus.

Mass Number - This means that the product mass number + the mass number of a helium nucleus = mass number of the original unstable nucleus.

Atomic Number - This means that the product atomic number + the atomic number of a helium nucleus = atomic number of the original unstable nucleus.

49
Q

In the equation E = mc2 , what does the m stand for?

A

The mass which is converted into energy, which is the difference in mass of the particles before the fission/fusion reaction and the mass after.

50
Q

What is the effect of an electric field on a charged particle?

A

The particle will experience a force that causes an acceleration.

51
Q

What information do you get from a chemical symbol, such as the one shown below?

A

Top number = Mass Number = number of protons and neutrons in the nucleus.

Bottom Number = Atomic Number = number of protons in the nucleus.

The letters are the chemical symbol which can be found on the periodic table.

52
Q

Describe the electric field around a negative charge.

A

Field lines towards negatively charged particle.

53
Q

What are the names of the 6 types of Quarks?

A
  1. Up
  2. Down
  3. Charm
  4. Strange
  5. Top
  6. Bottom
54
Q

What is the photoelectric effect?

A

The photoelectric effect is when electromagnetic radiation is directed at a metal surface and ejects electrons from the surface.

55
Q

Does a particle accelerator use a.c. or d.c. to create the electric field?

Explain why.

A

a.c.

This is because the electric field must change direction every time a particle completes a half circle (Dee) to keep the accelerating potential in the correct direction for the particles motion.

56
Q

A proton is made up of two up quarks and a down quark. The up quarks are both positively charged. Why does the proton not get torn apart?

A

Gluons carry the strong force to hold the quarks together. This strong force is greater than the force of repulsion between the particles.

57
Q

What is a Fermion?

A

It is a matter particle.

58
Q

What are the names of the 6 types of Leptons?

A
  1. Electron
  2. Electron neutrino
  3. Muon
  4. Muon neutrino
  5. Tau
  6. Tau Neutrino
59
Q

Describe the field lines between two positive charges.

A

Field lines run away from the positive charges. No field lines between them.

60
Q

What 2 conditions are required for nuclear fusion?

A
  • High Temperatures
  • High Pressure
61
Q

What will a moving charge experience in a magnetic field?

A

A force