Half-life

Radioactive substances

________ give out radiation from the nuclei of their atoms- no matter what.

Half life

________ can be used to find the rate at which a source decays- its ACTIVITY.

short half life

A(n) ________ means the activity falls quickly, because the nuclei are very unstable and rapidly decay.

Radioactivity

________ is a totally random process.

radioactivity of a source

The ________ decreases over time.

graph

you can measure half life using a__

number of radioactive nuclei

half-life is the time taken for the___________in an isotope to halve

rate of source decay

half-life is used to find the__________

random

radioactive decay is entirely________

more slowly

long half-life means activity falls____