P7 - Radiation Flashcards
What is meant by the ‘random nature of radioactive decay’?
can’t predict which nucleus will decay next
Name 2 sources of man made background radiation.
- x rays
- nucleur weapons
Name a nucleur fuel.
uranium
Describe the process of nucleur fission.
- small neutron = absorbed by uranium nucleus
- uranium nucleus splits -> 2 small nuclei
- and releases neutrons & emits gamma waves
What sort of reaction can nucleur fission stimulate?
chain reaction
What is also released during a nuclear fission reaction (other than neutrons & gamma waves)?
energy
What do you call an uncontrolled chain reaction?
nuclear explosion
Describe process of nucleur fusion and how it leads to the release of energy.
- lighter nuclei join -> form heavier nuclei
- some of mass is converted into energy
What is an advantage of of radioactive waste having a shorter half life?
less likely to cause harm
as activity ↓ quickly
Why is alpha radiation inside the body very dangerous?
- alpha radiation = highly ionising
- & likely -> cause cancer
- until radioactive material = removed
Define activity.
rate at which unstable nuclei decay
What is activity measured in?
Becquerel
Define count-rate.
number of decays recorded each second by detector
Why do nuclei decay radioactively?
to become stable
How does a nucleus become stable?
give out radiation
