GCSE Physics H

• Distance is a scalar quantity. This means that distance has magnitude, but does not have direction.
• Specific latent heat is the amount of energy required to change the state of 1kg of a substance without changing its temperature.
• The two types of specific latent heat are vaporisation and fusion.
• When a substance changes state, its mass is conserved.
• Alpha radiation is permitted to be used in household appliances because alpha radiation is completely contained within the appliance and alpha radiation is stopped by a few centimetres of air.
• Gamma radiation is dangerous because it has a high penetration ability and the people around it could be easily ionised by the radiation.
• Specific heat capacity is the amount of energy required to raise the temperature of 1kg of the liquid by 1 degrees.
• Containers should be insulated to minimise heat loss to the surroundings.
• The two hazards associated with handling radioactive materials are contamination and irradiation.
• Radioactive contamination is when particles of radioactive material are left on an object.
• The main factor which contributes to the seriousness of the hazard when an object is contaminated is the type of radiation emitted.
• Irradiated is when an object has come into contact with radiation. An irradiated object is not radioactive.
• Gamma radiation is often used to treat conditions such as cancer. Gamma rays can penetrate the body to kill cells internally. It is reasonably safe to use because it has a high penetration power and gamma will pass through most of the healthy cells without ionising them. Alpha radiation cannot be used for this purpose because it is not penetrative and it is stopped by a few centimetres of air.
• Alpha particles are made of two protons, two neutrons.