Radiation Flashcards
What is an isotope
Is an atom of the same element with the same number of protons but different number of neutrons
What is radiation
Isotopes can become unstable and emit radiation from their nucleus
Give the 4 main types of radiation
Alpha
Beta
Gamma
Neutron
What does it mean by a random process
We cannot tell when a single nucleus will decay
What is background radiation
The natural level of radiation that we find in air
Give some examples of background radiation
Radon gas (the air around us) Buildings, rocks and soil Cosmic rays Medical equipment Food and drink
Give the name of a detector that measure radiation levels
Geiger - Muller tube
What is an ion
An atom or a molecule with a charge
It can either be +ve or -ve
What is Ionisation
Is the REMOVAL or ADDITION of an ELECTRON to create an ION. Electrons can be lost from an atom because of ionising radiation
What is alpha radiation
Helium nucleus 2 protons and 2 neutrons Heavy Stopped by paper 10cm range in air
What is Beta
An electron
-1 charge
Stopped by a few mm of aluminium
1m range in air
What is Gamma
Electromagnetic wave
High energy
0 charge
Km’s range in air
What is neutron radiation
Neutrons are edited by radioactive material. They have roughly the same mass as a proton but have no electric charge (they are neutral)
As they are not electrically charged, neutrons emitted by a nucleus do not cause ionisation. They can be absorbed b other nuclei
What are the units we use for a radioactive source
Bq
What is a half life
The amount f time taken for half of the NUCLEI in a SAMPLE to decay.
The activity of a radioactive sample decreases over time
How do you find the half life on a graph
Calculated by halving the activity and checking the corresponding time, we do this more than once and the average
Give the dangers of alpha radiation
The most ionising radiation
Can only cause ham if it’s inside the body
Give the dangers of Beta and Gamma radiation
They have much less chance of ionising your cells. However they are able to penetrate the skin
What is irradiation
Is where someone is exposed to radiation
What is contamination
Is where we absorb radioactive material such as dust. This then emits radiation
Give 3 uses of radiation in the Industry
Gamma radiography
Gauging
Pipe tracers
What is radiography
Used to see through an object without destroying it
Certain materials are better at absorbing gamma rays ( allowing us to create an image of the object)
e.g X-rays at airports
What is Gauging
Can be used to measure the amount of material inside a tube or a container
It can also be used to determine the type or thickness e.g when pressing sheet metal
What are pipe tracers
Can be used to find a leak in the pipes
Radioactive gamma with a sort half life is ut in a liquid and run through a pipe.
When the amount of radiation in the surface changes, you have found a leak
What are medical tracers
Radioactive tracers which are used to investigate a patients body without the need for surgery. Gamma and Beta emitters are used as they can penetrate the skin whereas alpha can’t. A small amount of radioactive material is put into the patients body, a detector can then detect any Gamma or Beta rays that pass out the body
What is radiotherapy
Gamma rays are focused on the tutor to kill the cells. This is done by using a wide beam of gamma rays but rotating it around keeping the tutor at the centre.
What is sterilisation
Gamma rays pass through the packaging and inactivate viruses and kill bacteria. S long as the equipment remains in a sealed package, it will remain sterile.
Explain carbon dating
All living things absorb and emit radiation and so maintain a constant level while they are living.
When they die, this level is no longer constant. The Carbon-14 isotope that was present at death decays over time.
Because we know the half life of Carbon-14, we can measure the radioactivity of a fossil/skeleton and estimate how long it has been dead
