Radio activity Flashcards
what is the definition of an isotope
An element with the same number of protons but different number of neutrons so the mass number is different
Describe an Alpha Particle
Helium nucleus
low penetration ( stopped by paper)
Very Ionising
mass number of 4
Atomic number as 2
charge of +2
During radiation a helium nucleus is emitted from the nucleus
Describe a Beta particle
In radiation an electron is emitted from the nucleus.
Moderate ionisation
Moderate Penetration (stopped by Aluminium)
Describe a Gamma Particle
not very ionising
Very penetrating
List three radioactive particles
Beta
Alpha
Gamma
what is decay
the process of ejecting radiation
when a nucleus is unstable what does it do
It tries to become more stable, by either ejecting mass or energy
what do Becquerels measure (Bq)
Activity
what is the mass number and atomic number for beta
mass number-0
Atomic number-+!
the atomic number gains an electron
mass number remains unchanged
what is the mass number and atomic number for Gamma
mass number - 0
atomic number- 0
what is the mass number and atomic number for Alpha
mass number- 4
Atomic number- 2
what is Gamma stopped by
1km of air
10 cm of lead
what is Beta stopped by
1m of air
3mm of Aluminium
what is Alpha stopped by
3-7 cm of air
a single piece of Paper
Name the detector used to measure the penetration of different radioactive elements
GM tube
Geiger Muller tube
what are precautions used when handling radioactive elements
wear PPE- gloves, goggles
Use tongs- increase distance
Don’t point directly towards you
place source in a lead container
limit exposure time to radioactive element
what is the difference between beta and alpha
alpha has a larger mass and a bigger charge- means it is more ionising and less penetrating
alpha is a helium Nucleus
alpha has a a charge of +2 and a mass number of 4
Gamma is the odd one out state why
only element which is an electromagnetic wave
only one that doesn’t have a mass or a charge
Alpha and Beta are particles
Name sources of background radiation
cosmic rays
radon gas
Food/Drink
Humans
buildings
Nuclear power
Medical (x-rays)
Define HALF LIFE
the time taken for half the undecayed nuclei to decay
name two detectors for ionising radiation
GM tube- Geiger Muller tube
Photographic Film
what is meant by the term Irradiation
When someone is exposed to A/B/Y from a near by source
once the person moves away the irradiation stops
what is meant by the term Contamination
When someone gets particles of a radioactive source on their person or inside their body
they will continue to be exposed to radiation until the material has all decayed or it is removed
How is gamma source used to treat Cancerous tumours in the body.
The source is rotated around the tumour.
the gamma radiation always passes through the tumour, it receives a large does of radiation which will kill cancer cells
the gamma radiation does not pass through the same healthy tissue, it receives a lower dose, less damage
why does the doctor stay away from the patient
Increasing the distance decreases the count rate/ dose that the doctor receives.
this will cause less damage to the doctors body
( Which is important as they are exposed to radiation daily)
why is alpha not used for a radioactive tracer
because it is most ionising least penetrating
Alpha can be stopped by a single sheet of paper
if injected it can causes significant damage to internal organs
What is a chain reaction
Neutrons released in fission can be absorbed by other nuclei
these nuclei split (fission)
fission releases more neutrons
neutrons released in fission can be absorbed by other nuclei and so on
