# P1

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P1

Heat is a measure of energy and is measured in Joules.

Temperature is a measure of hotness and is measured in degrees Celsius.

Specific heat capacity is the amount of energy needed to raise the temperature of one kilogram of a substance or material by 1 degrees Celsius. Water has a heat capacity of 4200 joules/kilogram/degrees Celsius.

You need to put in energy to break intermolecular bonds.

When you heat a liquid, the heat energy makes the particles move faster.  When enough of the particles have gained enough energy to overcome their attraction to each other, large bubbles of gas form in the liquid – this is called boiling.

When you heat a solid the heat energy makes the particles vibrate faster until eventually  the forces between them are overcome and the particles start to move around  - this is called melting.

When a substance is melting or boiling, you’re still putting in energy, but the energy’s used for breaking intermolecular bonds rather than raising the temperature – they are the flat spots on the heating graph.

When a substance is condensing or freezing, bonds are forming between particles which releases energy. This means the temperature doesn’t go down until all the substance has formed into a liquid (condensing) or a solid (freezing).

Specific latent heat is the energy needed to change state.

The SLH of melting is the amount of energy needed to melt 1 kilogram of material without changing its temperature . (ie. The material has got to be at its melting temperature already.)

The specific latent heat of boiling is the energy needed to boil 1 kilogram of material without changing its temperature. (ie. Material has got to be at its boiling temperature already. )

Conduction occurs mainly in solids. Conduction of heat is the process where the vibrating particles pass on extra kinetic energy  to neighbouring particles. Heat flow is hot to cold.

Convection occurs in mainly liquids and gases. Convection occurs when the more energetic particles move from…