Radiation Flashcards
What is radiation?
Type of energy which moves from one place to another can be described as waves or particles.
What type of radiation is hazardous?
Ionising radiation is hazardous as it refers to when an electron is removed or gained and the atom becomes an ion.
What types of radiation are ionising
- All nuclear radiation
- Highest forms of electromagnetic radiation
Define ionising radiation
Radiation that has enough energy to remove an electron from an atom or molecule.
How to determine if a nucleus is stable or not?
The balance of protons and neutrons in the nucleus
How to determine if a element with fewer protons is stable?
The element will have equal protons and electrons.
What happens as elements gain more protons?
More neutrons are needed to stay stable, wont always be equal
What happens to unstable nuclei
They decay by emitting radiation
Will we be able to expect a nucleus to decay?
No, it is spontaneous and random, the process cant be sped up or slowed down and we cannot predict this.
What is Alpha radiation?
Alpha radiation refers to an unstable nucleus being able to emit a ‘package’ of 2 protons and 2 neutrons in order to become more stable.
What is alpha radiation made up of ?
A stream of ‘alpha particles’ emitted from an unstable nucleus
How are the mass and atomic number affected by alpha decay?
Mass - decreases by 4
Atomic Number - decrease by 2
What is beta radiation?
An unstable nucleus emitting a fast moving beta particle in order to become more stable
What is beta radiation made up of
A stream of beta particles emitted from an unstable nucleus
In what situation is beta radiation used
Emitted from nuclei where the neutron number is much higher then the proton
What can an unstable nucleus split into
A positive proton and negative electron
What happens as a result of beta decay?
The proton will remain in the nucleus and the electron will be ejected at a high speed
How does beta decay affect atomic number and mass ?
Mass - stays the same
Atomic number - goes up by 1 as theres an extra proton
When does gamma radiation come into play?
After alpha or beta radiation is used - The nucleus may be ‘excited’ and still need to lose energy.
How does the nucleus lose its energy after alpha / beta decay?
It will emit a high energy electromagnetic wave called a gamma ray
What is gamma radiation made up of?
high energy electromagnetic radiation
Are gamma rays emitted alone?
No, usually alongside Alpha or Beta radiation.
How does gamma ray emission effect mass and atomic numbers?
It doesnt, both atomic and mass number stay the same.
Define intensity?
Working out the Amount of energy - so we can work out how much energy we are delivering to patients.
What is the ‘formula’ for intensity?
Total energy per second, flowing past a unit area.
Define the Inverse square law
Electromagnetic waves travel in straight lines, meaning once generate they diverge
As we move away from point source, rad becomes weaker
We can measure the reduction in intensity using the ISL
Inverse Square Law
As distance away from source of rad, photons spread over a wider area
ISL
Photon energy at 2x the distance
spread over 4x the area
ISL
Photon energy at 3x the distance
Spread over 9x area
Radiation intensity Formula
Radiation intensity = 𝟏/𝒅²
