particle physics

• isotopes have same number of protons but a different number of neutrons
• A represents nucleon number (bigger)
• Z represents proton number (smaller)
• $\beta-$decay involves neutron turning into a proton with an antielecton neutrino
• $\beta+$decay involves a proton turning into a neutron with an electron neutrino
• nuclides refers to a specific isotope of an element
• in alpha decay, the proton number decreases by 2 and the nucleon number decreases by 4
• minimum energy of particles in par production is 2 x rest mass
• minimum energy of photons in annihilation is rest mass
• weak nuclear force happens in lepton hadron collisions
• electron capture is when a proton turns into a neutron after interacting with an electron through the weak interaction
• virtual photon is the exchange particle for the electromagnetic force
• W+ / W- boson are the exchange particle for the weak nuclear force
• Specific charge is inversely proportional to mass
• The only stable baryon is the proton
• Kaons decay into pions
• Neutrons decay into protons
• Power = photon energy x rate of emission
• the pion is the exchange particle of the strong nuclear force
• muons decay into electrons
• strange particles are always created in pairs
• the stopping potential is the potential difference needed to be supplied across a metal to stop the photoelectrons with maximum energy
• line spectra can be created by passing light through a diffraction grating
• each line in a line spectra will represent a different discrete wavelength of light which will correspond with a certain photon energy, showing photons can only exist in discrete energy levels
• de Broglie wavelength and momentum are inversely proportional
• in electron diffraction, a smaller wavelength will mean less diffraction and less diffraction will mean closer rings
• strange particles are those that are created by the strong force but decay by the weak force
• absorption spectra are created with the photons that are absorbed when an atom excites to a higher energy level
• emission spectra are created with the photons that are released when an atom de-excites
• the exchange particles in the weak interaction can be negative or positive to conserve charge
• the maximum kinetic energy of a photoelectron can be found using eVs
• a reverse voltage can be applied as a stopping potential such that eVs=Ekmax
• ground state is when an atom is in its lowest energy state
• in a fluorescent tube the mercury atoms release photons of UV
• there are always more lines on an emission spectrum than an absorption spectrum