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Radioactivity - Coggle Diagram
Radioactivity
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Radiation
KEY WORDS=
:pencil2: Half-life = the amount of time it takes for the activity of a radioactive substance to reduce by half
:pencil2: activity = number of decays per second
:pencil2: Radiation contamination = when an unwanted presence of materials contains radioactive atoms on other materials//when an object is exposed to ionising radiation but does not become radioactive
:pencil2: ionisation= radiation that can knock electrons from atom
:pencil2:irridated= when an object is exposed to ionising radiation
Half-life Graph: 
3 ways to reduce exposure to ionising radiation:
- keep far away as possible
- spend as little time as possible
- shield yourself using a thick lead barrier
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SHORT HALF-LIFE=
:!: Unstable nuclei disintegrate often
:!: substance is safe long term
:!: high activity
:!: substance hazardous due to high activity
LONG HALF-LIFE=
:!!: Unstable nuclei disintegrate rarely
:!!: low activity
:!!: substance remains radioactive for a long period of time so can be hazardous to store
Nuclear Radiation
Alpha Radiation:
- 2 protons and 2 neutrons (helium nucleus)
- absorbed by paper
- travel 5cm in the air
- high ionising power
- low penetrating power
EQUATION EXAMPLE;
Beta Radiation:
- high speed electron
- absorbed by thin aluminium
- can travel 2-3 metres in air
- medium ionising power
- medium penetrating power
EQUATION EXAMPLE;
Gamma Radiation:
- electromagnetic wave
- absorbed by thick lead
- infinite travel through air
- low ionising power
- high penetrating power
EQUATION EXAMPLE;
(No change to nucleus, no particles emitted)
Neutron Emission rules = when a neutron is emitted from the nucleus the mass number decreases by one but the atomic number stays the same
Nuclear Fission & Fusion
Nuclear Fission= when a large unstable nucleus splits into smaller nuclei releasing neutrons and energy
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:forbidden: Uranium nucleus absorbs a neutron
:forbidden: 2 smaller nuclei have been created
:forbidden: 2 or 3 more neutrons have been emitted
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Compare and Contrast nuclear fission and fusion (6 marks) EXAM-STYLE QUESTION
Nuclear fission is when a large unstable nucleus splits into smaller nuclei however nuclear fusion is the joining of two light atomic nuclei to form a larger one. When nuclear fission occurs using fuel Uranium-235 and Plutonium-239 these large nuclei absorb a neutron making nucleus split while releasing energy. the products of nuclear fission are known as radioactive waste and have to be stored for a very long time. This contrasts with Nuclear fusion as the products made from this is usually helium, when two isotopes of hydrogen come together, unlike nuclear fission helium is a useful gas and is not harmful to human life in any way. Even though Nuclear fission and Fusion has its differences both can be used to generate electricity, with both of them involving and atomic nuclei as well as that both release energy in the each reaction