ks4_p3_revision

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Revision forP3: Radioactive Materials : 

Revision forP3: Radioactive Materials Thursday, 05 August 2010 Learning Objective: To review the key areas in preparation for the P3 Exam.

Nuclear Radiation : 

Nuclear Radiation Comes from the nucleus Nucleus contains neutrons and protons Electrons orbit around the edge Nucleus Electrons Two isotopes of Carbon – both have 6 protons but different numbers of neutrons.

3 Types of Radiation : 

3 Types of Radiation Alpha Very ionising Not very penetrating Absorbed by paper or dead skin cells Stopped by only a few centimetres of air Beta Slightly ionising Absorbed by aluminium or half a metre of air Gamma Not very ionising Very penetrating Absorbed by lead or thick concrete

Efficiency : 

Efficiency Efficiency, as a percentage, is worked out by: The more efficient the object is the less energy is wasted or dissipated in an wasteful way Be able to interpret energy flow diagrams

Background Radiation : 

Background Radiation The dose of radiation is measured in sieverts Sv, or millisieverts mSv.

What happens when radiation hits a cell? : 

What happens when radiation hits a cell? Radiation passes straight through If it hits a sex cell it could cause a mutation by changing a gene Damaged – but repairs itself The DNA is damaged and the cell develops out of control – a cancer has begun It is killed

Energy Resources : 

Energy Resources Primary Energy Source: A source of energy not made from any other sort of energy source e.g. fossil fuels and uranium Secondary Energy Source: A source of energy that can be distributed easily but has been manufactured using a primary energy source e.g. electricity

Fossil Fuel Power Station : 

Fossil Fuel Power Station Be able to label a diagram like this

Nuclear Power Station : 

Nuclear Power Station Know the differences between these 2 diagrams

Fission : 

Fission Neutron

Chain Reaction : 

Chain Reaction Uncontrolled – causes a nuclear bomb Controlled – used in a power station

Half Life : 

Half Life The half life of a radioactive substance is the amount of time it takes for the activity (amount of radiation that is given out) to fall to half the previous value.

3 Types of Waste : 

3 Types of Waste Low Level e.g. protective clothing and medical equipment Packed in drums and put in a special landfill site Intermediate Level Less dangerous that high level waste High Level E.g. spent/old fuel rods This gets hot as it is so radioactive, it’s kept in a pool of water to absorb the heat

Health and Radioactive Materials : 

Health and Radioactive Materials Some questions will expect you to understand and / or discuss: ALARA Risks and Benefit Precautionary Principle Perceived risk and Actual risk