Nuclear Radiation Flashcards
What is the overall electric charge of an atom?
Atoms usually have an equal number of protons and electrons, giving the atom an overall neutral electric charge.
What are isotopes?
Atoms with the same number of protons in their nucleus but different numbers of neutrons.
What is a radioactive isotope?
An unstable isotope
How many main types of nuclear radiation are there?
Three main types: Alpha, Beta, Gamma.
What is the radiation symbol for alpha radiation?
α (helium nucleus, 2 protons and 2 neutrons).
What is the charge of alpha radiation?
+2.
What type of particle is beta radiation?
A fast-moving electron from the nucleus.
What is the charge of beta radiation?
-1.
What is gamma radiation?
A high-energy electromagnetic wave.
What is ionisation?
The process where an atom loses (or gains) an electron to become a charged ion.
Which type of radiation is the most ionising?
Alpha radiation.
Name one way to detect nuclear radiation.
Geiger Müller (GM) tube and counter.
What is the minimum absorber required for alpha radiation?
A few centimetres of air, paper, or skin.
What is the minimum absorber required for beta radiation?
A few millimetres of aluminium.
What is the minimum absorber required for gamma radiation?
Several centimetres of lead or thick concrete.
What is radioactive decay?
A random process where it is impossible to predict which individual nucleus will decay at a particular time.
What is activity in the context of radioactive decay?
The number of radioactive decays per second.
How many decays occur in a source with an activity of 50 Bq over 30 seconds?
1500 decays.
What is background radiation?
Radiation that is all around us, coming from natural and artificial sources.
What percentage of background radiation comes from natural sources?
85%.
What is dosimetry?
The way in which we can quantify the biological effect of radiation on humans.
What is the absorbed dose?
The energy absorbed per kilogram of mass.
What is the formula for calculating absorbed dose?
D = E/m.
What does the equivalent dose measure?
The biological harm caused by radiation.
