Topic 4 Isotopes And Nuclear Radiation Flashcards
What are isotopes
Different forms of the same element
Have the same number of protons and electrons but a different number of protons
What happens to unstable isotopes
Tend to decay into other elements and give out radiation as they try to become more stable
This process is called radioactive decay
Why might isotopes release neutrons when they decay
To rebalance their atomic and mass numbers
What is ionising radiation
Radiation that knocks electrons off atoms creating positive ions
What is the ionising power of a radiation source
How Easily it can knock electrons off
What type of radiation is the least penetrating
Alpha particles
Don’t penetrate very far and are stopped quickly
Can only travel a few cm in the air and are absorbed by a sheet of paper
Why are are alpha particles strongly ionising
Because of their size
How ionising are beta particles
Moderately ionising
Penetrate moderately far into materials before colliding and and range in air a few meters
They are absorbed by a sheet of aluminium around 5mm
What is the mass of beta particles
Negligible 
What happens for every beta particle that is emitted
A neutron in the nucleus has turned into a proton
What are gamma rays
Wave of electromagnetic radiation released by the nucleus
How penetrating are gamma rays
Penetrate far into materials without being stopped and will travel a long distance through the air
Why are gamma rays not ionising
Because they tend to pass through rather than collide with atoms
What can gamma rays be absorbed by
Thick sheets of lead or metres of concrete
What is alpha radiation used for
Smoke detectors
Ionises particles in the air causing current to flow
If smoke is in the air it binds to the ions meaning the current stops and the alarm sounds
