Particles

Question 1

Alpha decay

Answer 1

The process of an unstable nucleus emitting an alpha particle to become more stable. Usually in nuclei that have too much mass.

Question 2

Annihilation

Answer 2

The process of a particle and antiparticle colliding and being converted into energy. The energy is released in two photons moving in opposite directions to conserve momentum. The rest mass energy of the particle and antiparticle pair is converted into energy of the photons. Need to show particles convert to 2 photons of equal energy and the relationship, E=hf

Question 3

Antiparticle

Answer 3

All particles have a corresponding antiparticle with the same mass but opposite charge and conservation numbers.

Question 4

Baryon number

Answer 4

quantum number that is conserved in all particle interactions.
Baryons have a baryon number of +1 and non-baryons have a baryon number of 0.

Question 5

Beta-Minus Decay

Answer 5

The process of a neutron inside a nucleus turning into a
proton, and emitting a beta-minus particle (an electron) and a antineutrino.

Question 6

Beta-Plus Decay

Answer 6

The process of a proton inside a nucleus turning into a
neutron, and emitting a beta-plus particle (a positron) and a neutrino.

Question 7

Electron Diffraction

Answer 7

The spreading of electrons as they pass through a gap
similar to the magnitude of their de Broglie wavelength. It is evidence of the
wave-like properties of particles.

Question 8

Electron-volt (eV)

Answer 8

The work done to accelerate an electron through a potential difference of 1V. 1eV is equal to the charge of an electron (E=qv).

Question 9

Energy Levels

Answer 9

Defined and distinct energies at which electrons can exist in an
atom. An electron cannot exist between energy levels.

Question 10

Excitation

Answer 10

The process of an electron taking in exactly the right quantity of
energy to move to a higher energy level.

Question 11

Gauge Boson

Answer 11

The exchange particles that transmit the four fundamental
interactions between particles.

Question 12

Ground State

Answer 12

The most stable energy level that an electron can exist in.

Question 13

Hadrons

Answer 13

A class of subatomic particle that experiences the strong nuclear
interaction.

Question 14

Ionisation

Answer 14

The process of an atom losing an orbital electron and becoming
charged.

Question 15

Isotope:

Answer 15

Same number of protons but different numbers of neutrons.

Question 16

Isotopic Data

Answer 16

Data from isotopes that can be used for a purpose, such as carbon dating.

Question 17

Kaon

Answer 17

A type of meson that decays into pions.

Question 18

Lepton Number

Answer 18

A quantum number that is conserved in all particle interactions. Both electron lepton numbers and muon lepton numbers must be conserved

Question 19

Lepton

Answer 19

A group of elementary subatomic particles, consisting of electrons,
muons and neutrinos.

Question 20

Meson

Answer 20

A class of hadron that is made up of a quark and antiquark pair.

Question 21

Muon

Answer 21

A type of lepton that decays into electrons.

Question 22

Neutrino

Answer 22

A subatomic particle whose existence was hypothesised to maintain the conservation of energy in beta decay

Question 23

Nucleon Number (A)

Answer 23

The sum of the number of protons and neutrons in a given nucleus.

Question 24

Nucleon

Answer 24

A proton or neutron

Question 25

Pair Production

Answer 25

The process of a sufficiently high-energy photon converting into a particle and its corresponding antiparticle. To conserve momentum, this usually occurs near a nucleus.

Question 26

Photon

Answer 26

A packet of energy

Question 27

Pion

Answer 27

A type of meson and the exchange particle for the strong nuclear force.

Question 28

Positron

Answer 28

A positively charged particle that is the antiparticle of an electron.

Question 29

Proton Number (Z)

Answer 29

The number of protons present in the nucleus of a given
element.

Question 30

Stopping Potential

Answer 30

The minimum potential difference required to stop the
highest kinetic energy electrons from leaving the metal plate in the photoelectric effect.

Question 31

Strange Particles

Answer 31

Particles that are produced through the strong interaction but decay through the weak interaction.

Question 32

Strangeness

Answer 32

A quantum number that is conserved in strong interactions but not in weak interactions. This reflects that strange particles are always produced in pairs.

Question 33

Strong Nuclear Force

Answer 33

A force that acts between nucleons in a nucleus to keep it stable. It is attractive at distances of up to 3fm and repulsive at separations less than 0.5fm.

Question 34

Threshold Frequency

Answer 34

The minimum frequency of photons required for photoelectrons to be emitted from the surface of a metal plate through the
photoelectric effect. It is equal to the metal’s work function divided by Planck’s constant.

Question 35

Work Function

Answer 35

The minimum energy required to remove an electron from a
metal’s surface.