nuclear decay, radioisotopes and half-life

what happens during alpha decay?

the mass number decrease by 4 and the atomic number decreases by 2

what happens during beta-minus decay?

the mass number stays the same and the atomic number increases by 1

what happens during gamma decay?

the mass number and atomic number stay the same

what must be balanced in a nuclear equation?

mass number and atomic number

what particle is released during alpha decay?

a helium nucleus

what particle is released during beta-minus decay?

an electron

what is half-life?

the time taken for half of the radioactive nuclei in a sample to decay

a sample starts at 100 g. How much remains after one half-life?

50 g

A sample starts at 100 g. How much remains after two half-lives?

25 g

a sample starts at 80 g. How much remains after three half-lives?

10 g

what happens to radioactive material over time?

the amount decreases as more nuclei decay

what does a radioactive decay curve look like?

a decreasing exponential curve

how can you find half-life from a decay graph?

find the time taken for the amount of radioactive material to decrease to half its original value

what is carbon - 14 used for?

dating materials that were once living

why can carbon-14 be used for dating?

it decays at a predictable rate

how are radioisotopes used in medicine?

for medical imaging, diagnosis and treating some diseases

how are radioisotopes used in industry?

to detect leaks and measure the thickness of materials

how are radioisotopes used in energy production?

nuclear reactors use radioactive materials in fission reactions to release energy