Year 8 Physics

Activity

The number of radioactive decays per second

Electromagnetic spectrum

the entire range of electromagnetic waves of various wavelengths

electromagnetic waves

waves that travel via light and do not require a medium to propagate

energy

the ability to do work

half-life

the time taken for half of the radioactive nuclei in a sample to decay or the time taken for the activity of a sample to decrease by half

ion

a particle with an unequal number of protons and electrons

ionising radiation

radiation with high enough energy to remove an electron from its atom

isotopes

atoms with the same number of protons, but a different number of neutrons

Law of Conservation of Energy

states that energy can only be transformed or transferred, but not created or destroyed (except in a nuclear reaction)

mechanical waves

waves that travel via particle oscillation and require a medium to propagate

nuclear radiation

radiation that is emitted from the nucleus of an atom

radiation

the transfer of energy via particles or waves

radioactive decay

the process by which an unstable parent nucleus transmutes into a daughter nucleus by emitting nuclear radiation

Electromagnetic spectrum order

Radio waves, microwaves, infrared, visible light, ultra violet rays, X - rays, gamma rays