Particles

• proton (nucleus)

• neutron (nucleus)

• electron (orbitals)

1 and +1

1 and 0

0.005 and -1

• atom or group of atoms

• same no. of protons and neutrons

• same no. protons

• diff no. neutrons

radioactive decay

• carbon dating to determine ages of organic materials

• ~6000 years

charge per unit mass

C kg^-1

mass = no. of nucleons × 1.67×10^-27

nuclear charge = no. of protons × 1.60×10^-19

ion charge = no. of electrons gained/lost × 1.60×10^-19

strong nuclear force

alpha or beta decay

• <0.5 fm: repulsive

• 0.5 fm - 3 fm: attractive

• >3 fm: negligible

1 fm

• parent nucleus releases alpha particle

• decays in to smaller (daughter) nucleus

nuclei are too large for SNF to hold them together

• neutron turns to proton and electron (beta particle)

• anti electron neutrino is released

when there is a large ratio of neutrons to protons in a nucleus

• proton turns to neutrons and positron (beta-plus particle)

• electron neutrino is released

when there is a large ratio of protons to neutrons in a nucleus

• electron neutrino (and anti)

• muon neutrino (and anti)

to conserve energy during beta decay

• particles that experience SNF

• baryons and mesons

quarks

• contain 3 quarks

• protons and neutrons

• quark and anti quark

  • pions and kaons

• baryon: +1

• anti-baryon: -1

• non-baryon: 0

they are the only stable baryon