Nuclear Physics

Test T4W1 Tues

Atomic Number

number of protons

Atomic Mass

number of protons + number of neutrons

Nucleons

collective term for protons and neutrons held together by strong nuclear force

Strong Nuclear Force

force that holds protons and neutrons together, it is also responsible for the energy released in nuclear reactions

Electromagnetic Force

force that holds opposing charges together, e.g. protons and electrons

Alpha Radiation

size: large
speed: slow
penetration: some cells
ionising ability: strong
stop: paper

Beta Radiation

size: 1/2000 AMU (small)
speed: 98% SOL
penetration: medium
ionising ability: medium
stop: 5mm aluminum foil

Gamma Radiation

size: no size (wave photon)
speed: SOL
penetration: very high
ionising ability: 0, but can cause other atoms to
cause it
stop: lead (high density substances)

Half-life

the time it takes for one half of the atomic nuclei of a radioactive sample to decay

Isotopes

atoms with the same number of protons but different number of neutrons. isotopes with complete electron shells are more stable and have longer half-lives because they are less reactive and have a low energy state

Fission

the splitting of a large atomic nucleus into smaller nuclei called ‘daughter nuclei’. two or more neutrons also explode out of the reaction and these can collide with other nuclei to cause a chain reaction

Fusion

when two small, light nuclei join together to make a heavy nucleus. As two nuclei approach each other, they will repel because they have the same charge. The fusion of the nuclei has to happen quickly so the repulsion does not have time to stop it from happening.

Energy Changes

fusion:
fission: