Section G Radioactivity Flashcards
Where does background radiation come from?
Substances from Earth (air, food, building materials, soil, rocks…)
Space (cosmic rays)
Name three types of radiation that can be given out when unstable nuclei decay.
Gamma rays, beta particles, alpha particles.
What charge are beta particles?
Negatively charged (they’re electrons).
What charge are alpha particles?
Positive charge (they’re helium nuclei).
What is ionisation?
When atoms (with no charge) are bashed into other atoms and having electrons knocked off them. They turn into ‘ions’.
What are alpha particles made out of?
2 protons and 2 neutrons.
What can stop alpha penetrating power?
Paper, skin.
What can stop beta penetrating power?
Thin metal (aluminium).
What stops gamma penetrating power?
Thick lead or very thick concrete.
What is meant by the term isotope?
Atoms with the same atomic number but a different mass number.
What detector could be used to detect the radiation of any particle or wave?
Geiger-Muller Tube.
What happens to the atomic number and the mass number of a nucleus when it undergoes beta decay?
The nucleus in the atom turns into a proton and an electron; so the atomic number increases, but the mass number stays the same.
What is meant by the term ‘unstable’ in terms of radioactivity?
It will decay and give off radioactive particles.
