Stable and unstable nuclei

Cards (8)

State a use of radioactive isotopes
Carbon dating - the proportion of carbon-14 in a material can be used to determine its age
What is the strong nuclear force
The fundamental force that keeps the nuclei stable by counteracting the electrostatic force of repulsion between protons
Describe the range of the strong force
Repulsive up to 0.5fm
Attractive from 0.5-3fm
Negligible past 3fm
What makes a nucleus unstable
Nuclei which have either too many protons/neutrons or both
How do nuclei with too many nucleons decay
Alpha Decay (emission of a helium nucleus formed of 2 protons and 2 neutrons)
How do nuclei with too many neutrons decay
Beta minus decay (neutrons decays into a proton via the weak interaction, udd to uud)
How was the existence of the neutrino hypothesised
Energy of particles after beta decay was lower than before, a particle with 0 charge and negligible mass must carry away this energy, this particle is the neutrino
What is meant by beta minus decay
when a neutron turns into a proton, the atom releases an electron and an anti-electron neutrino