1. Physics REVISION – Expansion of Solids and Liquids
When solids are heated its molecules gain kinetic energy and vibrate more vigorously.  As the vibration become larger, the molecules are pushed further apart and the solid expands slightly in all directions. The opposite happens when a solid cools so the solid contracts slightly in all directions. Expansion and contraction is minimal. A metre rule will expand 1-2mm when heated. The temperature, size and material of the object impacts how much expansion occurs.
The contraction of solids has to be considered in the design of everyday objects. For example bridges and telephone wires. On a hot day concrete bridges expand. To solve this problem, we leave small gab at one end and support the other end with rollers. Telephone wire contract on cold days.  To solve this problem, we leave wires slack so that they are free to change length.
A Bimetal strip is a two-thin strips of different metals welded together, when is heated, the brass expands more than invar and this makes the strip bend.  If the strip is cooled, instead of heated, it would bend the opposite way.
A Bimetal strip is used in a Thermostat. The control knob sets the desired temperature. The switch opens and closes an electrical circuit which turns the thermostat on and off. The bimetal strip provides the expansion and contraction which results closing or opening of the switch depending on the temperature of the room. Too hot the bimetal bends and opens the switch, turning off the heating. Too cold the bimetal strips bends the other way closing the switch therefore turning the heating back on.
When a liquid is heated its molecules gain kinetic energy and vibrate more vigorously.  As the vibration become larger, the molecules are pushed further apart and the liquid expands slightly in all directions. Liquids expand much more than solids and expansion is effected by temperature, volume and liquid type
When a liquid is initially heated the liquid level drops due to the expansion of its container which initially absorbed all the heat.  After a while, the heat reaches the liquid it compensates for the expansion of the container and rises much more than the original level. Liquid expansion is used in Thermometers.
Ice vs Water - When water freezes it changes to ice and  its volume increases by about 9%. The increase in volume means that the ice is less dense than water beneath it and it will floats.  In ice the water molecules link up producing a fixed structure that takes up more space.

2. Physics REVISION – Measurement of Temperature
The are 3 main liquid-glass-thermometers
Mercury, Alcohol and Clinical thermometers
Liquid-in-glass thermometers have 5 main parts:
1- Glass tube  2-Bulb 3-Liquid 4-Thread 5-Scale
Liquid-in-glass thermometers have a bulb which contains liquid (e.g. mercury, alcohol) which expands when temperature rises and pushes a thread of liquid along the scale where temperature can be read.
Mercury thermometers conduct heat well and responds quickly to changes in temperature however are expensive and poisonous plus freezes at -39°C. so not suitable for low temperatures. Alcohol on the other hand freezes at -115 °C but has to be coloured in to be seen.
Define temperature :Temperature is a measure of the average kinetic energy possessed by each molecule of the substance.
The physical properties that are used to measure temperatures:
Expansion of materials in Liquids: mercury, alcohol and in Solids: Thermocouple
Thermistor: Change in electrical resistance due to temperature.
Thermometer key words:
Sensitivity: is the ability of a thermometer to detect small changes in temperature.
Range: is the range of temperatures which can be measured by the thermometer
Linearity (uniformity): the expansion of the liquid should be linear (uniform, the same) for all different temperatures measured.
We can increase the sensitivity of a thermometer by increasing in the volume of the bulb and decreasing the diameter of the tube (bore).
We can increase the range of a thermometer by decreasing in the volume of the bulb and increasing the diameter of the tube (bore). 
Fixed points are established so other temperatures can be compared to them or calibrated against them. The Celsius scale has a lower fixed point and an upper fixed point
In the Celsius scale the lower fixed point is the temperature of pure melting ice - 0°C. The upper fixed point is the temperature of steam above pure boiling water under standard atmospheric pressure - 100°C.
Other common used fixed points are: boiling point of liquid oxygen -183 °C, freezing point of molten silver 962 °C and freezing point of molten gold 1064 °C
The Kelvin Scale is the same as the Celsius scale except it starts from absolute zero.  The a one degree Kelvin is equal to one-degree Celsius.
Absolute-zero is the lowest temperature in the universe and at this temperature the molecules of a substance have the minimum possible energy.  It occurs at -273°C.
TK=TC+273 where TK is temperature in Kelvin and TC is temperature in Celsius.
A Thermocouple consists of a mechanical junction of two dissimilar metals. This junction generates a small electrical potential (voltage), the value of which depends upon the temperature of the junction.
The bigger the temperature difference between the two junctions, the greater the electric current (the thermocouple is not linear). Thermocouples can be calibrated, by an appropriate choice of metals, to create a thermometer for the desired temperature range.
Thermocouples are very sensitive and can measure rapidly changing temperatures, measure high temperatures and can be read easily and logged (recorded) in a computer.

3. Physics REVISION – Thermal Capacity and Specific Heat
Thermal Capacity is often defined to be the amount of thermal energy required to raise the temperature of 1 kg of a substance by 1 Kelvin or 1 °C
Obviously, different substances have different thermal capacities. The Thermal capacity of 1kg of water = mass x specific heat capacity of water = 1kg x 4200J(kg°C) = 4200J/°C
Thermal capacity is also dependent on mass, the greater the mass of water the higher it’s thermal capacity.
Now if you are talking at about raising an objects temperature by more the 1°C then you need to take into account temperature rise also. Now the energy required to increase an object of specific mass, to a specific temperature is calculated as follows:
Energy transferred = mass x specific heat capacity x temp change
Mass in Kg, shc (c) in J/Kg°C and temp change in °C or K
Temperature is a measure of the average kinetic energy possessed by each molecule of the substance. Internal energy is defined as the energy associated with the random, disordered motion of molecules. Consider a beaker of water passively resting on a table. At microscopic level, the kinetic energy of moving molecules is part of the internal energy of the system. The potential energy of the molecules arising from the intermolecular interaction forms the other part of the internal energy of the system.
To measure specific heat capacity of an object:
Set up a circuit with a heater, voltmeter, ammeter, and have a stopwatch to hand.
Measure the mass of the material you are going to heat. Time how long it takes to reach the desired temperature.
Measure the amount of energy required to raise temperature of block (E=Ivt) by a certain amount of degrees using the circuit.
Now using the equation: E = m x c x ΔT
Rearrange to get c=E/ m x ΔT
To calculate the Specific Heat capacity of the material.
Since Kinetic Energy proportional to temp, and internal energy of the system = sum of its Kinetic Energy and Potential Energy, a rise in temperature will cause a rise in Kinetic Energy (molecules move more vigorously) and thus an increase in internal energy.
If two bodies are in thermal equilibrium, there is no net flow of heat energy between them and they have the same temperature. {NB: this does not imply they must have the same internal energy as internal energy depends also on the number of molecules in the 2 bodies, which is unknown here}
High specific heat capacity, such as in water, is useful for transporting or storing thermal energy. Eg in a heating system the boilers heat the water which then travels around the heating pipe system to radiators where it slowly releases the heat into the required rooms.

4. Physics REVISION – Melting, Boiling and Latent Heat
Describe condensation and solidification.
Condensation: This is the change of the physical state of
matter from a gas into a liquid. Condensation usually forms on a cold surface. E.g Steam on a bathroom shower. Particles of gas cool down, (therefore loose kinetic energy) slow down and start by the form clusters with nearby gas particles causing a liquid to form.
Solidification: This is the change of the physical state of matter from a liquid to a solid. E.g. changing water into ice cubes. You put the water into the fridge, and it freezes to become ice. Liquid particles join to form bonds in a regular lattice shape. This is what causes expansion upon freezing. This hexagonal lattice contains more space between particles than the liquid state and because the particles are more spread out ice is less dense causing it to float.
Describe melting and boiling in terms of energy input without a change in temperature. There are two types of energy in every substance, which we often refer to this as internal energy. The two types of energy are potential and kinetic energy.
The kinetic energy is what defines the temperature of the substance. When the temperature of a substance reaches a state where it is ready to go through boiling or melting, energy is still being transferred but the temperature is still constant. This is shown on the graph as a horizontal line.
In this process, bonds are being broken or formed, so
energy transfer is definitely required for this change in
state. However, if the kinetic energy doesn’t change
here but the potential energy increases instead. The
energy is either used to create bonds (potential to be released if the bonds are broken in future ie the change of state is reversed) or to break the bonds previously formed.
The differences between boiling and evaporation:
1.Boiling occurs in the body of a liquid whereas evaporation only happens at the surface of a liquid.
2. Evaporation can happen at any temperature, as long there is enough Kinetic Energy to break the bonds between the liquid particles so they escape as a gas, boiling however can only happen at certain temperatures, e.g. 100°C for water.
Latent Heat is the quantity of heat absorbed or released by a substance undergoing a change of state. When water goes through a change of state from liquid to gas it absorbs heat energy in order to break the bonds between particles. Latent Heat of Vaporisation is the energy required to change 1kg water into steam. It’s 2,300,000j/kg meaning 2,300,000j of energy is required to 1kg of water to steam at 100 °C
Energy transferred when water is vaporised Q = mL
Q = power x time and m = mass
Power = voltage x current
To measure specific latent heat of vaporisation of water
Water to Ice: Latent Heat of Fusion is the energy required to change 1kg ice into water. It’s 330,000j/kg meaning 2,300,000j of energy is required to 1kg of ice o water at 0 °C
Energy transferred when ice melts Q = mL Calculate the total energy (in Joules) delivered to the heater from the equation: Q = IVt then calculate the mass of melted water due to the heater only.The divide the energy by mass to get the latent heat of fusion L = Q/m