solids, liquids and gases

• How to calculate the density of a solid experimentally

  1. Measure the mass of the solid using a balance.
  2. If the shape is regular, measure the volume of the solid using geometry.
  3. If the shape is irregular, measure the volume of the solid by adding it to a Eureka can filled with water. This will cause a volume of water exactly equal to the volume of the solid to flow into the measuring cylinder.
  4. Use the formula to calculate the density of the solid from the mass and volume measurements.
• At higher elevation (altitude) the gas particles are more spread out, so they generate less pressure. 
• How volume affects pressure in a gas

  1. Decreasing the volume of the container, whilst keeping the number of gas particles the same, will increase the concentration.
  2. In this smaller volume, collisions between particles of gas and the walls of the container will be more frequent.
  3. A greater number of collisions per unit area of wall means the pressure increases.