Particle model of matter

• Describe the arrangement of particles in a solid

  • all touching
  • regular pattern
  • vibrate around a fixed position
  • fixed shape and volume
• Describe the arrangement of particles in a liquid

  • close together
  • random arrangement
  • move around each other
  • fixed volume but shape can change
• Describe the arrangement of particles in a gas

  • far apart
  • random arrangement
  • move quickly and randomly in all directions
  • no fixed shape or volume
• In which state of matter are the interactions between particles greatest?

  Solids
• Name the change of state when a solid changes to a liquid

  Melting
• Name the change of state when a liquid changes to a gas

  Boiling
• Name the change in state when a solid changes to a gas

  Sublimation
• Name the change in state when a gas changes to a liquid

  Condensing
• Name the change in state when a liquid changes into a solid

  Freezing
• Can a solid be compressed?

  No
• Can a liquid be compressed?

  No
• Can a gas be compressed?

  Yes
• Write the equation linking density, mass and volume

  Density = mass/volume
• Which state of matter has the highest density?

  Solids
• Which state of matter has the lowest density?

  Gas
• State how we can calculate the volume of an object with a fixed shape (cube or cuboid)

  By using a ruler to measure the length, height and width, then multiplying these together
• Why might we use a Vernier calliper or micrometre Screw gauge to measure the length rather than a ruler?

  They have a higher resolution so measurements should be more precise
• State how we can measure the volume of an irregular shape

  By carrying out the displacement method using either a Eureka can or measuring cylinder
• Name the equipment used to measure the mass of an object

  A balance
• Name the type of error cause when a balance does not start at zerp

  A zero error
• State two ways in which we can rectify a zero error

  Re-zero the equipment if it is digital or we can subtract the error from our readings
• State whether changes of state are physical or chemical changes

  Physical changes
• What is a physical change?

  The substance recovers its original properties if the change is reversed
• Define 'internal energy'

  The sum of the kinetic and potential energy of all the particles in a substance
• What does heating a system do to its internal energy?

  Increases internal energy by increasing the average kinetic energy of the particles
• What happens when the temperature of a substance increases?

  There is an increase in the average kinetic energy of the particles
• What happens when a substance changes state?

  There is an increase in the potential energy of particles in order to change the arrangement of the particles
• Define 'specific heat capacity'

  The amount of energy required to increase the temperature of one kilogram of the substance by one degree Celsius
• Define 'specific latent heat'

  The energy required to change the state of one kilogram of the substance at a constant temperature
• Write the equation linking energy change, mass, specific heat capacity and change in temperature

  Change in thermal energy = mass x specific heat capacity x temperature change
• What are the units for specific heat capacity?

  J/kg C
• State the symbol used to represent temperature change

  ∆θ
• Write the equation linking energy, mass and specific latent heat

  Energy for a change of state = mass x specific latent heat
• State the units of specific latent heat

  J/kg
• Define 'specific latent heat of fusion'

  The energy required to change the state of one kilogram of a substance from solid to liquid, at a constant temperature
• Define 'specific latent heat of vaporisation'

  The energy required to change the state of one kilogram of a substance from liquid to gas, at a constant temperature
• What is the average kinetic energy of a gas related to?

  Its temperature
• State what happens to the pressure of a gas, at a constant volume, if you increase the temperature

  the pressure increases
• State what happens to the motion of molecules in a gas as its temperature increases

  Velocity increases
• Explain why the pressure of gas (at fixed volume) increases with temperature

  A greater temperature means that particles have more kinetic energy. This indicates that they are moving with greater velocity which means that there will be more frequent collisions between particles and the container. There will therefore be more force per unit area which means that pressure will increase.