Thermal physics

• What is the internal energy of a gas?

  Sum of kinetic and potential energies
• What can be said about the internal energy of an ideal gas?

  It equals the kinetic energy of particles
• What is specific heat capacity?

  Energy to raise 1 kg by 1 degree
• What equation calculates energy required to raise temperature?

  E = mc(change in T)
• What is activation energy?

  Minimum energy for a chemical process
• What does the gradient of a temperature-energy graph represent?

  1 / Specific Heat Capacity
• How do particles transfer energy between themselves?

  Through random collisions with each other
• What is the formula for energy in relation to temperature?

  E = $\frac{2 kT}{3}$
• What is the term for the energy required for chemical processes to occur?

  Activation energy
• What happens if $\frac{2 kT}{3}$ is less than the activation energy?


  The reaction will be unable to occur
• At what range of activation energy do reactions occur at an appreciable rate?

  Between 15kT and 30kT
• How do particles exchange energy?

  Through random collisions
• What determines the probability of a particle gaining enough energy to move to a higher energy level?

  Random collisions
• How does the number of particles on each energy level change?

  It decreases exponentially with each level up
• What is the Boltzmann factor?

  The ratio of particles on different energy levels
• If the Boltzmann factor is ½, what does this indicate?

  It is the ratio of particles between adjacent levels
• What does the Boltzmann factor depend on?

  The process involved in energy movement
• What does the Boltzmann factor ratio represent?

  The "jump" involved in energy levels
• What is the equation for the Boltzmann factor?

  $f_B =$$e^{-\frac{\epsilon}{kT}}$
• What does each symbol in the Boltzmann factor equation represent?

  f_B = Boltzmann factor, e = exponential factor, ε = activation energy, k = Boltzmann constant, T = temperature
• What is the unit of temperature in the Boltzmann factor equation?

  Kelvin
• What are the three mechanisms of heat transfer discussed?

  Conduction, convection, and radiation
• How does conduction work in materials?

  Heat energy is distributed through vibrations
• What happens to metal ions when heated?

  They vibrate more rapidly
• How do vibrating metal ions transfer energy?

  They pass energy to adjacent atoms
• What is the process of energy transfer in a heated metal rod?

  Energy is transferred continuously along the rod
• What is the temperature threshold for bodies to emit radiation?

  Greater than 0 Kelvin
• What happens to particles at absolute zero?

  They are essentially motionless
• What factors control how much radiation a body can emit or absorb?

  Temperature, surface area, and surface type
• How does a dull, matte surface affect radiation?

  It is a good absorber and emitter
• How does temperature affect the nature of radiation emitted?

  Higher temperature means higher frequency radiation
• What is the relationship between energy and frequency in radiation?

  Higher energy means higher frequency
• What causes heat transfer in liquids and gases?

  Density variations and pressure differences
• What happens to the volume of air in a balloon when air is blown into it?

  The volume of air increases
• What forces act on a balloon when air is added?

  Internal pressure and atmospheric pressure
• How does a particle exert pressure on the walls of a container?

  By bouncing off the surface and changing momentum
• How is pressure quantified in a container?

  Pressure = force divided by area
• What assumptions are made in the kinetic theory of gases?

  No forces between particles, negligible volume
• What is assumed about the collisions of particles in kinetic theory?

  They are elastic and no energy is lost
• What is the assumption about the force between particles in a gas?

  It is negligible.