Particles Flashcards
What is an isotope
Isotopes are atoms with the same number of protons but with different number of neutrons
How to calculate specific charge
Charge divided by mass
What is the role of the strong nuclear force
Keeping the nucleus stable
What is the range of the strong nuclear force
Attraction up to 3fm, but repulsion closer than 0.5fm
What causes radiation
Unstable nuclei
What is alpha decay
When an unstable nuclei releases 2 neutrons and 2 protons together as an alpha particle
What is beta decay
When an unstable nuclei decays a neutron to become a proton, releasing an electron and an antineutrino
What is gamma radiation
When a nucleus with a lot of energy releases electromagnetic radiation ,that can pass through metal plates
Why is a neutrino required
Conservation of energy in beta decay
What are photons
A packet of electromagnetic waves
What is a laser beam
It consists of photons of the same frequency; the equation for its power = nhf
For every type of particle…
There is a corresponding antiparticle
Properties of antiparticles
Same rest mass as the particle, exactly opposite charge to the other particle
What is the name of the antiparticle of electrons
Positrons
What is annihilation
When a particle and its antiparticle meets, their mass is converted into energy as two photons (hf = E)
What is pair production
When a photon creates a particle and its own antiparticle randomly (hf = 2E)
What are the four fundamental interactions
Gravity, electromagnetic, weak nuclear and strong nuclear forces
What are exchange particles for
Explaining change in energy, momentum and forces in interactions
What is the exchange particle for the electromagnetic force
Virtual photon
What is the exchange particle for weak interaction
W+, W-
What is the exchange particle for strong interaction
Pion
What is beta- decay
Neutron into proton and W-
W- into antineutrino and electron
What is beta+ decay
Proton into neutron and W+
W+ into positron and neutrino
What is electron capture
Proton into neutron and W+
W+ and electron into neutrino
What is proton-electron collision
Electron into neutrino and W-
W- and proton into neutron
Describe what electron capture is
Electron from an orbital interacts with a proton in the nucleus via weak interaction, to form a neutron
Proof that electrons act like a particle
Deflection of electrons in an electric field
Proof that electrons act like a wave
Diffraction of electrons
Describe pair production
Photon interacts with an electron/atom, energy is used to make a particle-antiparticle pair, hf=2mc^2, conserves momentum
