P2 - Atoms And Ionising Radiation Flashcards
Describe the isotopes of an atom.
One or two stable ones, the rest are radioactive.
What do radioactive substances do?
Give out radiation from their nuclei no matter what is done to them.
What is the process of radioactive decay?
Random.
What happens to radioactive decay when you alter the temperature or bond the atom?
Nothing, it remains random and unaffected.
Where does background radiation come from? [3].
1) naturally occurring unstable isotopes.
2) space.
3) man-made sources.
Where does background radiation from naturally occurring unstable isotopes come from? [4].
Air, food, building materials, rocks.
Where does background radiation from space come from?
Cosmic rays from the Sun.
Where does background radiation from man-made sources come from? [3].
1) fallout from nuclear weapons tests.
2) nuclear accidents.
3) dumped nuclear waste.
What are alpha particles the same as?
Helium nuclei.
What makes up an alpha particle?
Two neutrons & two protons.
Describe the properties of alpha particles [6].
Big, heavy, slow.
Not far penetrating, stopped quickly even in air, strongly ionising.
Why are alpha particles strongly ionising?
They are big they hit a lot of atoms and knock electrons off them.
What are beta particles?
Electrons.
What are the properties of beta particles? [5].
Quite fast, quite small.
They penetrate moderately, have long range, are moderately ionising.
What happens when a beta particle is emitted?
A neutron turns into a proton in the nucleus.
What are gamma rays?
Very short wavelength EM waves.
What are the properties of gamma rays? [3].
Deeply penetrating, pass straight through air, weakly ionising.
What happens with gamma rays eventually?
They hit something and do damage.
What is the mass and charge of gamma rays?
None.
What are isotopes?
Atoms with the same number of protons but different number of electrons.
What is radiation dose?
The type and amount of radiation.
The higher the radiation dose..
The more at risk you are of developing cancer.
What does the radiation dose you’re exposed to depend on?
Location and occupation.
What does radioactive radon gas tend to do?
Get trapped in people’s houses.
What precautions do nuclear industry workers take? [3].
Protective clothing, face masks, monitor their radiation.
How do radiographers prevent radiation exposure? [2].
Lead aprons and stand behind lead screens.
How does altitude affect radiation exposure?
Higher altitude means more exposure to cosmic rays.
What happens to alpha and beta particles when travelling through a magnetic or electric field?
They are deflected in opposite direction.
Compare the deflection of an alpha particle to a beta particle in a magnetic or electric field.
Alpha particles will be deflected less because they have a greater mass.
What happens to gamma rays travelling through an electric or magnetic field?
Nothing - it has no charge.
