1.3

• explain how the motion of the molecules in a gas is related to it temperature and pressure

  Molecukes in a gas are in constant random motion -changing the temperature of a gas at a constant volume ,changes the pressure exerted by the gas.
• explain the relationship between the temperature of a gas and its pressure at a constant volume

  When the temperature is increased the gas particles move faster and the collisions become harder /more frequent -meaning the pressure increases
• recall that gases can be compressed and heated to increase their volume and pressure
• Explain how increasing the volume in which a gas is contained at a constant temperature can lead to a decrease in pressure

  There's more space so less frequent collisions with the walls of the container exerting lower pressure
• Explain how workdone on a gas can be to an increase in its temperature

  The temperature in a gas isn't fixed and the increased pressure leads to an increase in temperature so an increase in the energy store of a gas means temperature must increase
• Atmospheric pressure

  Atmospheric pressure - In the atmosphere releases pressure on us all of the time .the atmosphere of the Earth is a mixture of gases that surround the Earth
• Explain why atmospheric pressure varries with height above the surface of the planet

  Because as altitude increases the number of air molecules decrease so there's less air above the planet
• Describe the factors which influence floating and sinking

  density mass and volume of objects