Particles Flashcards
(27 cards)
Define isotopes.
Atoms with the same proton number, but a different nucleon number, due to a difference in the number of neutrons.
Is the strong nuclear force attractive or repulsive?
Both. It is repulsive below a distance of 0.5 x10^-15 m, but attractive at greater distances than this.
What’s the exchange particle for the strong nuclear force?
A pion.
What are the two products of alpha decay?
The daughter nucleus, and an alpha particle.
What are the 3 products is beta-minus decay?
The daughter nucleus, a beta-minus particle (fast-moving electron) and an anti-electron neutrino, to conserve lepton number.
What are the 3 products of beta-plus decay?
The daughter nucleus, a beta-plus particle (fast-moving positron) and an electron neutrino, to conserve lepton number.
What are the products of electron-capture?
Daughter nucleus, an electron neutrino and the emission of an X-ray photon, due to the energy difference between the inner shell and the nucleus.
What do kaons decay into?
Pions.
What happens when a particle and its corresponding antiparticle meet?
Annihilation. Their energy is converted to 2 electromagnetic photons, to conserve momentum.
What happens in pair production?
A single photon becomes a particle and its corresponding antiparticle.
What do exchange particles transfer?
Energy, momentum and force.
What’s the exchange particle of the electromagnetic force?
A virtual photon.
What’s the exchange particle of the weak nuclear force?
Bosons.
What’s the exchange particle of gravity?
The graviton.
Which fundamental forces have infinite range?
The electromagnetic force and gravity.
What’s the range of the strong nuclear force?
2 x10^-15 m.
What’s the range of the weak nuclear force?
1 x10^-18 m.
Which exchange particle features in beta-minus decay?
Negative boson.
Which exchange particle features in electron capture?
Positive boson.
Which exchange particle features in and electron-proton collision?
Negative boson.
Particles can be divided into two main categories: hadrons and leptons. What’s their difference?
Hadrons feel the strong nuclear force; leptons don’t.
What two categories can hadrons be divided into?
Baryons and mesons.
What’s the difference between baryons and mesons?
Baryons decay to produce a proton; mesons don’t. Also, baryons consist of 3 quarks, whereas mesons consist of a quark-antiquark pair.
What do mesons eventually decay into?
Leptons.
