Radioactivity Flashcards
What is meant by radioactivity?
When istopes have a unstable nucleas the nuclease releases radiotion to become stable.
What are the 4 types of radiation?
gamma ray
beta particle
alpha particle
neutron
What is activity?
Rate at which unstable nuclei decay
What are the properties of gamma rays?
Penetrate far into material
They travel long distances in air
Weakly ionising because they pass through rather than collide with atoms
Absorbed by concrete and lead
What are the properties of alpha particles?
Don’t penetrate far into materials
Travel a few cm in air
Absorbed by sheet of paper
Strongly ionising because of size
What are the properties of beta particles?
Moderately ionising
Moderately penetrates far into material
Travels a few m in air
Absorbed by aluminium 5mm
Every beta particle emitted a neutron turns into a proton
What is the definition of half life?
Time it takes for amount of radiation emitted by a source to halve.
What is radioactive contamination?
When unwanted radioactive isotopes ends up on other material.
How is radioactive contamination hazardous?
Because radioactive atoms decay and emit ionising radiation.
Describe alpha radiation (contamination
strongly ionising but easily stopped by cells on skin surface.
can be dangerous as it can be swallowed or inhaled and can damage skin cells.
Describe beta radiation (contamination)
quite ionising and can penetrate the skin into body.
Describe gamma radiation (contamination)
Weakly ionising can penetrate body but likely to pass through.
Describe gamma radiation (contamination)
Weakly ionising can penetrate body but likely to pass through.
