Section 7 Flashcards
How can we detect ionising radiation?
Photographic film or a Geiger-Muller detector.
What are alpha particles?
Helium nuclei
What does emitting an alpha particle do to an atom?
Decrease the atomic number of the nucleus by 2 and the mass number by 4.
What are beta particles?
Electrons
What do beta particles do to an atom when released?
Increase the atomic number by 1 and the mass number remains the same.
What are gamma rays?
Very short wavelength EM waves.
How can alpha be blocked?
Paper, skin.
How can beta particles be stopped?
Thin metal.
How can gamma rays be stopped?
Thick lead or very thick concrete.
When being shot through a substance what happens if the alpha particle is travelling fast?
The less it will be deflected by the nucleus.
What will happen to an alpha particle if the nucleus is more positively charged?
The more the alpha particle will be deflected.
What is a half life?
The time taken for half of the radioactive atoms now present to decay.
What makes beta and gamma suitable for medical tracers?
They will penetrate the skin and other body tissues.
Why is gamma used in industrial tracers?
So the radiation can be detected through any rocks or earth surrounding the pipe.
Why does the gamma have to have a short life when being used in industrial tracers?
So not to cause a long-term hazard if it collects somewhere.