P2.5 Flashcards
What is ionising radiation?
Radiation that has enough energy to cause atoms to lose electrons and become ions
What is wrong with the nucleus of a radioactive particle ?
It is unstable
How does an unstable nucleus become more stable?
It decays to become more stable by losing energy when certain types of ionising radiation are emitted form the nucleus
What is an alpha particle ?
A particular clue that has two protons and two neutrons but no electrons
Why do alpha particles have a short penetration distance ?
They produce many ions in a short distance so they lose energy quickly
What are beta particles ?
They are electrons that are emoted from an unstable nucleus
What are beta particles penetration distance ?
They are much less ionising than alpha particles and so can penetrate much further into matter than alpha particles can
What are gamma rays?
They are high frequency electromagnetic waves emitted by some unstable nuclei
What are gamma rays penetration distance ?
They are 10 times less ionising than beta particles and can penetrate matter very easily
What is nuclear fission?
When large unstable nuclei , split into two smaller nuclei called daughter nuclei
What is an uncontrolled chain reaction?
When an unstable nucleus releases a proton and it gets absorbed by another nucleus which then becomes unstable and releases more neutrons into other nuclei.
What is nuclear fusion?
when small nuclei can be combined to form larger ones. this also releases a lot of energy
How do nuclear reactors work?
They Transform energy contained in the nuclei of uranium and plutonium atoms into thermal energy using nuclear fission
What does a moderator do?
It slows down the movement of neutrons in a nuclear reaction
