Particle

Nucleon number (large number written next to atomic element symbol), A

Number of neutrons + number of protons in the nucleus

Proton number (atomic number), Z

Number of protons

The atomic mass unit

1/12 the mass of a carbon 12 nucleus

u = 1.66 x 10^-27 kg - written on data book

Ion

An atom with an access charge (may have more / less nuclei). Most likely an electron has been stripped from the atom.

Isotope

An nucleus with the same number of protons but with a different number of neutrons

Nuclide

A nucleus with a certain proton and nucleon number

Specific charge and its units

=net charge / total mass

Charge per unit mass Unit: C kg^-1

Specific charge of a regular atom

ZERO

Calculating the specific charge of a nucleus

(proton number x charge of electron) / (nucleon number x atomic mass number )

Specific charge of an alpha

(2 x e) / ( 4 u ) Since proton number = 2 and nucleon number = 4

Which particle has the largest specific charge

an electron (smallest mass)

Key features of the strong force

Very short range. It is attractive between 3 f m and 0.5 f m (f: 10^-15). It is repulsive when nucleons are closer than 0.5 f m . It does not depend on charge.

What is an alpha particle ?

A helium nucleus (proton number = 2, nucleon number = 4)

What is a beta minus?

A high speed electron ejected from a nucleus

What is a beta plus?

A high speed positron (anti electron) ejected from a nucleus

Why did physicists believe a neutrino was also involved in beta decay?

Beta was ejected with a range of K.E's (hence velocities). They should not be ejected with a K.E less than the maximum. If it was a two particle recoil the beta particles would be emitted with one velocity.

There is a set amount of energy in the system

There must be another particle to conserve energy

Similarities and differences between particles and their anti particles

They have the same mass and rest energy. They have the opposite charge.

What is the anti particle of an electron

A positron

What is the anti particle of an proton

An anti proton

What is the anti particle of an neutron

An anti neutron

The definition of a photon

A packet of electromagnetic energy The energy = h f

The energy of a photon

E = h f = h c / wavelength

What is annihilation?

When an particle and anti particle touch their mass is converted to energy - two gamma photons travel in opposite directions to conserve momentum

2 rest energy’s + 2KEs if applicable =2 photon E

What is pair production?

When a gamma photon produces a particle anti particle

Photon energy = 2 rest energy’s + 2 ke (if applicable to question)

State the four fundamental interactions

The strong force The weak interaction The electromagnetic force Gravitational force

What is a Boson ?

An exchange particle responsible for particles exchanging a force

The Bosons responsible for the weak interaction

W plus or minus bosons

Interactions involving the weak force

Beta plus, Beta minus, electron capture and Muon decay. Where quarks change form

The particles involved in beta minus decay

A neutron decays into a proton and electron as well as an anti neutrino (to conserve lepton number) udd is converted to uud an electron and anti neutrino

The boson involved in beta minus decay

W minus (see http://www.antonine-education.co.uk/Pages/Physics_1/Particles/PP11/particles_page_11.htm )

The particles involved in beta plus decay

A proton decays into a neutron and positron as well as a neutrino (to conserve lepton number). uud is converted to udd a positron and a neutrino.

The boson involved in beta plus decay

W plus (see http://www.antonine-education.co.uk/Pages/Physics_1/Particles/PP11/particles_page_11.htm )

The Bosons responsible for the electromagnetic force (the force between charges)

Virtual photons

What is the charge of an up quark

+2/3

What is the charge of an anti up quark

-2/3

What is the charge of a down quark

-1/3

What is the charge of an anti down quark

+1/3

What is the quark composition of a proton

uud

What is the quark composition of a neutron

udd

What is the strangeness of an up and down quark

zero

What is a Hadron?

A particle which experiences the strong force (The Baryon(qqq) and mesons (q, anti q) families of particles are all Hadrons).

What is a Baryon

A particle which consists of three quarks

What is the Baryon number of a single quark?

1/3

What is the Baryon number of a single anti quark?

-1/3

Name particles which are baryons and have baryon number = 1

Proton Neutron Sigma (contains a strange quark) Lambda (contains a strange quark)

Name particles which are baryons and have baryon number = -1

Anti Proton Anti Neutron Anti Sigma (contains a strange quark) Anti Lambda (contains a strange quark)

Name the Baryon which all other Baryons will eventually decay into (when outside the nucleus)

The proton (it is the most stable Baryon)

What is a Meson

A quark anti quark

What is the baryon number of a Meson?

Zero (since is is a q, anti q this has a baryon number = 1/3 - 1/3 = 0 )

State the meson which is passed between protons and neutrons and is partly responsible for the mediation of the strong force?

The pion

State a strange meson

The Kaon

What is the quark composition of a pion+

U, anti d

What is the quark composition of a pion zero (no charge)

d, anti d u, anti u

What is the quark composition of a Kaon plus

u, anti s

What is the quark composition of a Kaon zero (no charge)

d, anti, s

State the particle which a Kaon decays into

A combination of pions. Strangeness is not conserved as the weak interaction changes quarks

What is a Lepton

A fundamental particle (does not experience the strong force)

State as many leptons as you can

Electron Positron Neutrino Anti Neutrino Muon (a heavy electron) Anti Muon Muon neutrino Anti Muon neutrino Tau (A very heavy electron) Anti Tau Tau neutrino Anti Tau neutrino

State a lepton which has a Lepton number of +1

Electron Neutrino Muon Muon neutrino Tau Tau neutrino

State a lepton which has a Lepton number of -1

Positron Anti Neutrino Anti Muon Anti Muon neutrino Anti Tau Anti Tau neutrino

What does a Muon decay into?

A Muon decays into an electron, Muon neutrino (to conserve muon Lepton number) and an anti Neutrino (to conserve electron Lepton number)

What quantities are conserved in any reaction?

Baryon number Lepton number Proton number Mass - energy equivalence (Never say mass or energy)

What are the properties of strange particle (containing a strange quark)

They are always produced in pairs (strangeness is conserved on production) via the strong force. They decay very slowly via the weak force (on decay strangeness is not conserved - they do not decay in pairs).

What is the charge of a strange quark?

-1/3

What is the charge of an anti strange quark?

1/3

What is the strangeness of a strange quark?

-1

What is the strangeness of an anti strange quark?

+1

When is strangeness conserved?

On creation via the strong interaction

When is strangeness not conserved?

On decay via the weak force.

How are theories within particle Physics verified?

Particle physics relies on the collaborative efforts of large teams of scientists and engineers to validate new knowledge via experiments (particle accelerators).

How will a free neutron decay

A neutron will decay into a proton, electron and anti neutrino (to conserve Lepton number). This is the same as beta minus decay.