Solids, Liquids and Gases

• What is density?


  The mass of particles per unit volume.
• What is pressure?


  The force per unit area.
• What is the unit for density?


  kg/m3 or g/cm3
• What is the unit for pressure?

  Pascals, Pa
• What is the density of water?

  1000 kg/m3
• Objects that are less dense than water do what?

  They float.
• How do you calculate pressure difference in fluids?

  pressure difference=density*height* gravitational field strength
• Describe the movement of particles in a solid.

  They vibrate about their fixed positions.
• Describe the movement of particles in a liquid.

  They move/flow/slide over eachother.
• Describe the movement of particles in a gas.

  They move around freely and randomly at high speed in all directions
• What does heating a system increase?

  It increases the average kinetic energy of particles.
• What can happen when the Average Kinetic energy of particles is increased?

  -The temperature of the system will increase

  -There will be a change of state
• What is specific heat capacity?

  It is the amount of energy required to increase the temperature of 1 kilogram of a substance by 1 degree Celcius.
• What is the unit for s[ecific heat capcity?

  Joules/kg 'C
• What is the equation for specific heat capacity?

  Change in thermal energy=mass*specific heat capacity*change in temperature
• What is Brownian motion?

  It is the random motion of tiny particles in a fluid.
• How does Brownian motion provide evidence that air is made up of smaller particles?

  -Large particles such as pollen move around randomly in the air

  -This is due to them colliding with smaller particles that are invisible to the naked eye
• What is Absolute zero?

  It is the temperature at which the molecules have zero kinetic energy this is 0K and -273 degrees Celsius .
• true or false: The kelvin scale starts at 0 so it will never have a negative value.

  True.
• How do you convert from Degrees Celsius to Kelvin?

  Add 273.
• What is an ideal gas?

  an ideal gas is a gas that has molecules with no volume and no interactions. It has molecules that do not deform.
• What is the relationship between Pressure and temperature at a constant volume?

  As temperature increases pressure increases
• What is the relationship between pressure and volume at a constant temperature?

  if the volume is compressed the pressure increases, if the volume is expanded the pressure decreases.
• What is the formula for pressure and volume at a constant temperature

  p1V1=p2V2
• What is the formula for pressure and temperature at a constant volume?

  p1/T1= p2/T2