Topic 08: Nuclear and Particle Physics

Question 1

Antimatter

Answer 1

A particle with the same mass/rest energy as its matter particle, but with opposite charge and opposite quantum numbers. A particle and an antiparticle will annihilate to create a photon

Question 2

Baryon

Answer 2

A particle consisting of three quarks. Protons and neutrons are both baryons. The most stable baryon is the proton, and so all baryons eventually decay to the proton

Question 3

Baryon number

Answer 3

A measure of if a particle is a baryon. It is +1 for a baryon, -1 for an antibaryon, and 0 for any other particle

Question 4

Cyclotron

Answer 4

A particle accelerator that has two semicircular electrodes with a gap between. When a charged particle is in the electrodes it is curved due to the magnetic field perpendicular to the plane of the electrodes. When it is in the gap, it accelerates in an alternating voltage electric field resulting in a spiral path and accelerated charged particle

Question 5

Fundamental particles

Answer 5

Particles that cannot be broken down into smaller constituents

Question 6

Gauge boson

Answer 6

Fundamental particles that are the carriers of the fundamental forces

Question 7

Gluon

Answer 7

Gauge boson of the strong interaction

Question 8

Hadron

Answer 8

Particles that undergo strong interactions, they are made up of quarks so include mesons and baryons

Question 9

Lepton

Answer 9

Fundamental particles that do not interact via the strong force. They can transform between flavours via the weak interaction and some have charge so undergo electromagnetic interactions. They include the electron, electron neutrino, muon, muon neutrino, tau, and tau neutrino

Question 10

Lepton number

Answer 10

A measure of if a particle is a lepton. It is +1 for a lepton, -1 for an antilepton, and 0 for any other particle

Question 11

Linac

Answer 11

Linear accelerator. These accelerate charged particles through sets of oscillating electric fields that create large electric potentials that accelerate the particles

Question 12

Meson

Answer 12

A particle consisting of one quark and one antiquark. Pions and kaons are examples of mesons

Question 13

Nucleon number

Answer 13

The number of neutrons and protons in the nucleus

Question 14

Photon

Answer 14

Gauge boson of the electromagnetic force

Question 15

Plum pudding model

Answer 15

A model of the atom that describes it as a ball of positive charge with evenly distributed negative electrons throughout it

Question 16

Proton number

Answer 16

The number of protons in the nucleus

Question 17

Quark

Answer 17

Fundamental particle that interacts with other quarks via the strong interaction. It will change flavour via the weak interaction and annihilate with antiquarks to form photons via the electromagnetic interaction. They come in six flavours: up, down, charm, strange, top, bottom

Question 18

Quark confinement

Answer 18

The principle that states that quarks cannot exist alone and must be either in quark, antiquark pairs, or threes

Question 19

Relativistic motion

Answer 19

Particles that are travelling at close to the speed of light. They will experience time at a slower rate than a non-relativistic particle

Question 20

Strangeness

Answer 20

A measure of how many anti-strange quarks a particle has. A K+ is formed of an up and antistrange, so has strangeness +1. A K- is formed of a strange and an antiup, so has strangeness -1

Question 21

Thermionic emission

Answer 21

When a metal is heated, free electrons gain sufficient kinetic energy and are released from the metal’s surface

Question 22

Weak interaction

Answer 22

The force that causes flavour change in quarks and leptons. It is responsible for beta decay

Question 23

W+/W-/Z0

Answer 23

Gauge bosons of the weak interaction