Flash Cards
What’s meant by specific charge
Charge/mass
C/kg
What’s the letter associated for a proton number and nucleon
Protons
Z
Nucleon
A
How do nuclei with too many nucleons decay
Alpha decay
What’s the use of radioactive isotopes
Carbon dating - the proportion of carbon-14 in a material can be used to estimate its age
What’s the strong nuclear force
The fundamental force that keeps the nucleus stable by counteracting the electrostatic force of repulsion between protons
Describe the range of the strong force
Repulsive up to 0.5fm
Attractive from 0.5-3fm
Negligible past 3fm
What makes a nucleus unstable
Nuclei which have too many of either protons or neutrons or both
How do nuclei with too many neutrons decay
Beta minus decay in which a neutron decays to a proton by weak interaction
How do nuclei with too many neutrons decay
Beta minus decay in which a neutrons decays to a proton by the weak interaction
How was the existence of the neutrino hypothesised
The energy of particles after beta decay was lower than before, a particle with 0 charge
What’s meant beta minus decay
What’s a neutron turns into a proton, the atom releases an electron and an anti-electron neutrino
What’s an alpha particle
A particle contains two protons and two neutrons, the same as a helium nucleus
What’s is an antiparticle
For each particle there is an antiparticle with the same rest energy and mass but all other properties are the opposite of its respective particle
What’s the antiparticle of an electrons
Positron
What is the antiparticle of pi0
It’s an antiparticle of itself
What occurs when a particle and antiparticle meet
Annihilation,
The mass of the particle and antiparticle is converted back to energy in the form of 2 gamma ray photons which go in opposite directions to conserve momentum
What is pair production
A gamma ray photon is converted into a particle antiparticle pair
What is the minimum energy of a photon required to make a proton antiproton pair
2 x proton rest energy
2x938.26
Name the 4 fundamental forces
Gravity
Electromagnetic
Weak nuclear
Strong nuclear
The virtual photon is the exchange particle of which forces
The electromagnetic force
What type of particles are affected by the strong nuclear force
Hadrons
What is the exchange particle of the weak nuclear force
The W boson
What does the electromagnetic force act on
It acts on charged objects, for example when a positively charged ball repels another positively charged ball
When does weak nuclear interaction occur
When quark character changes, it affects all types of particles
