Topic 1 - Particles

Question 1

Alpha Radiation

Answer 1

Particles that each consist of two protons and two neutrons.

Question 2

Annihilation

Answer 2

When a particle and its antiparticle meet, they destroy each other and become radiation.

Question 3

Antibaryon

Answer 3

A hadron consisting of three antiquarks.

Question 4

Antimatter

Answer 4

Antiparticles that each have the same rest mass and, if charged, have equal and opposite charge to the corresponding particle.

Question 5

Antimuon

Answer 5

Antiparticle of the muon.

Question 6

Antineutrino

Answer 6

The antiparticle of the neutrino.

Question 7

Antiparticle

Answer 7

There is an antiparticle for every type of particle. A particle and its corresponding antiparticle have equal rest mass and, if charged, equal and opposite charge.

Question 8

Antiquark

Answer 8

Antiparticle of a quark.

Question 9

Atomic Number (Z)

Answer 9

The number of protons in the Nucleus of an Atom.

Question 10

Baryon

Answer 10

A hadron consisting of three quarks.

Question 11

Beta Radiation

Answer 11

Beta- particles are fast moving electrons emitted by unstable neutron-rich nuclei; Beta+ particles are fast moving positrons emitted by unstable proton-rich nuclei.

Question 12

Conservation rules

Answer 12

Conservation of energy, momentum, charge, baryon number and lepton number applies to all particle interaction. Conservation of strangeness applies to strong interactions only.

Question 13

Electromagnetic interaction

Answer 13

Interaction between two charged objects.

Question 14

Electron Capture

Answer 14

Process in which an inner-shell electron of an atom is captured by the nucleus.

Question 15

Energy

Answer 15

The capacity to do work.

Question 16

Gamma radiation

Answer 16

High-energy photons emitted by unstable nuclei or produced in particle annihilations.

Question 17

Hadron

Answer 17

Particles and antiparticles that can interact through the strong interaction.

Question 18

Isotopes

Answer 18

Atoms of an element with different numbers of neutrons and the same number of protons.

Question 19

Kaon (or K meson)

Answer 19

A meson that consists of a strange quark or antiquark and another quark or antiquark.

Question 20

Lepton

Answer 20

Electrons, positrons, muons and antimuons, neutrinos and their antiparticles are classified as leptons because they cannot interact through the strong interaction. They interact through the weak interaction and, in the case of electrons and positrons, through the electromagnetic interaction.

Question 21

Lepton Number

Answer 21

A lepton number is assigned to every lepton (+1) and antilepton (-1), on the basis that the total lepton number for each branch of the lepton family is always conserved.

Question 22

Meson

Answer 22

A hadron consisting of a quark and an antiquark.

Question 23

Muon

Answer 23

A lepton that is negatively charged and has a greater rest mass than the electron.

Question 24

Neutrino

Answer 24

Uncharged lepton with a very low rest mass compared with the electron.

Question 25

Neutrino types (or ‘branches’)

Answer 25

There are three types of neutrinos, the electron neutrino, the muon neutrino, and the tau neutrino. This Specification only requires knowledge of the electron neutrino and the muon neutrino branches (and their antiparticles) of the lepton family.

Question 26

Nucleon

Answer 26

A neutron or proton in the nucleus.

Question 27

Nucleon number A

Answer 27

The number of neutrons and protons in a nucleus; also referred to as the mass number.

Question 28

Nuclide

Answer 28

A type of nucleus with a particular number of protons and neutrons.

Question 29

Pair production

Answer 29

When gamma photon changes into a particle and an antiparticle.

Question 30

Pion

Answer 30

A meson that consists of an up or down quark and an up or down antiquark.

Question 31

Positron

Answer 31

Antiparticle of the electron.

Question 32

Quark

Answer 32

Protons and neutrons and other hadrons consist of quarks. There are six types of quarks, they are: up, down, strange, charm, top and bottom. The specification requires only that students know the up, down and strange quarks.

Question 33

Quark model (or standard model)

Answer 33

A quark can join with an antiquark to form a meson or with two other quarks to form a baryon. An antiquark can join with two other antiquarks to form an antibaryon.

Question 34

Rest energy

Answer 34

Energy due to rest mass, equal to m0c^2 where c is the speed of light in a vacuum and m0 is the rest mass.

Question 35

Specific charge

Answer 35

Charge/mass value of a charged particle.

Question 36

Strangeness number

Answer 36

A strangeness number is assigned to every particle and antiparticle on the basis that strangeness is always conserved in the strong interaction, but not in the weak interaction or a decay involving a strange quark or antiquark.

Question 37

Strong interaction

Answer 37

Interaction between two hadrons.

Question 38

Strong nuclear force

Answer 38

Attractive force between nucleons that holds the nucleons in the nucleus.

Question 39

Virtual photon

Answer 39

Carrier of the electromagnetic force; a photon exchanged between two charged particles when they interact.

Question 40

W boson

Answer 40

Carrier of the weak nuclear force; w bosons have a non-zero rest mass and may be positive or negative.

Question 41

Weak interaction

Answer 41

Interaction between two leptons

Question 42

Weak nuclear force

Answer 42

Force responsible for beta decay.