Particles Flashcards
What is the atomic number and what is its symbol
The number or protons, symbol Z
What is the mass number and what’s its symbol
The number of nucleons with the symbol A
What is an isotope
An atom with the same number of protons but different number of neutrons
What are radioactive isotopes used for
To find out how old stuff is by using carbon-14 to carbon date objects
What is specific charge
The ratio of charge to its mass
What force acts on nucleons
The strong nuclear force
Describe how strong nuclear force acts dependent upon separation
- it’s repulsive up to 0.5fm
- after that it’s an attractive force
- the strength of the force quickly decreases after about 1fm
- it falls near to 0 at 3fm
Compare the electrostatic force and strong nuclear force within the nucleus
- the electrostatic is always repulsive but SNF is only repulsive up to 0.5fm
- the electrostatic force has an infinity range but SNF has a short range
- SNF is stronger than electrostatic at short distances
When would a particle emit alpha particles
It happens in big nuclei like uranium and radium, when they are too massive for the SNF
What particle would emit beta- particles
When a nucleus is neutron rich(too many neutrons)
What happens in beta - decay
A neutron changes into a proton and electron and instantly emits and electron and an antielectron neutrino
What experiment hypothesised neutrinos
Beta decay
What is a photon
A packet of electromagnetic radiation
Which has a longer wavelength radio waves or gamma rays
Radio waves
Which has a higher frequency gamma rays or radio waves
Gamma rays
What happens when you turn energy into mass
You get equal amounts of matter and anti-matter
What is pair production
When energy (photon) is converted into a particle and its antiparticle
How much energy must a photon have in order to undergo pair production
It must have twice the amount of the particles rest energy
Where does pair production happen and why
Close to the nucleus to conserve momentum
What is annihilation
When a particle meets its antiparticles, all of the mass gets converted into energy which creates two photons of equal energy
What are exchange particles called
Gauge bosons
What is the gauge boson for electromagnetic force and what is affected
Virtual photons, it affects charged particles
What is the exchange particle for the weak force and what does it affect
W+ and W- it affects all types of particles
What is the exchange particle for the strong force and what particles does it affect
Pions and it affects hadrons only
