Science Flashcards
Why an element is radioactive
Having an unstable nucleus with an unstable amount of protons and neutrons
Description of alpha particles
Slow moving protons and neutrons
Description of beta particles
Fast moving electrons
Description of gamma radiation
High energy electromagnetic wave
Beta particles are stopped by
Thin sheet of aluminium
Alpha particles are stopped by
Thin sheet of paper
Gamma radiation is stopped by
Thick sheet of lead
3 types of radiation
Alpha
Beta
Gamma
Explain why an alpha source is used in the pacemaker rather than beta or gamma
Alpha will not escape the pacemaker as it’s made of metal, beta and gamma would escape and damage the tissue
Why’s it important for a radioactive source to be long lasting
So It will not need replaced often
Definition of background radiation
It’s radiation that is all around us and always present
Unit of activity
Becquerd (BQ)
Counts per minute
Ionisation
It’s the gain or loss of electrons to form an ion
How does a graph show if background radiation is taken into account
The radioactivity levels drop to zero
Ionising radiation
Is radiation emitted from an unstable nucleus
Half life
The time taken for activity to fall by half
In Industry radiation is used for
used to control the thickness of materials as it passes through the rolling mill
(Aluminium)
Medicine radiotherapy
Radiotherapy is the use of radiation in medicine to kill cancer cells
Radiation used for medicine
Gamma rays are used to penetrate deep inside the body and target the tumour and are rotated to not destroy healthy cells
Agriculture radiation is used for
Gamma radiation is to treat fresh fruit by killing any bacteria or fungi stopping it from decaying
Agriculture
The food will stay fresher for longer an preserve extending its shelf life
Sources of background radiation
Carbon 14 in living organisms
Radioactive gas (radon) emitted from granite rock
Traces of potassium’s in some foods
Waste products from nuclear power stations
Medicine in hospitals
Cosmic rays
