Fundamental Particles Flashcards
(22 cards)
α-particle scattering experiment
Showed nucleus is small and dense
α-radiation
Helium nucleus (2 protons, 2 neutrons), +2 charge, high ionization
β− radiation
Electron, -1 charge, low mass, medium ionization
β+ radiation
Positron, +1 charge, low mass, medium ionization
γ-radiation
Electromagnetic wave, no charge, no mass, low ionization
Antiparticle
Same mass, opposite charge to particle
Positron
Antiparticle of electron, +1 charge
β− decay
Electron and antineutrino emitted
β+ decay
Positron and neutrino emitted
Energy of α-particles
Discrete
Energy of β-particles
Continuous due to neutrino emission
Unified atomic mass unit (u)
Unit of mass for atomic particles
Quark
Fundamental particle, six types
Quark flavors & charge
Up: +2/3, Down: -1/3, Strange: -1/3, Charm: +2/3, Top: +2/3, Bottom: -1/3
Proton composition
uud (up, up, down)
Neutron composition
udd (up, down, down)
Hadrons
Particles made of quarks, either baryons or mesons
Baryon
Three quarks (e.g., proton, neutron)
Meson
One quark, one antiquark
β− decay quark change
Neutron (udd) → Proton (uud) + e− + antineutrino
β+ decay quark change
Proton (uud) → Neutron (udd) + e+ + neutrino
Leptons
Fundamental particles including electrons and neutrinos
