Particles and Radiation

Question 1

Alpha Decay

Answer 1

The process of an unstable nucleus emitting an alpha particle (two protons and two neutrons) to become more stable.

Question 2

Annihilation

Answer 2

The process of a particle and its antiparticle colliding and being
converted into energy. The energy is released in two photons to conserve momentum.

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

A 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

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

Hadrons

Answer 11

A class of subatomic particle that experiences the strong force

Question 12

Ionisation

Answer 12

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

Question 13

Isotope

Answer 13

Same number of protons. Different number of neutrons

Question 14

Pair Production

Answer 14

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 15

Stopping Potential

Answer 15

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

Question 16

Strong Nuclear Force

Answer 16

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 17

Threshold Frequency

Answer 17

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 18

Work Function

Answer 18

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