What should I know?

1. Temperature is a measure of the average kinetic energy of the particles of a substance.
2. Particle motion consists of translational, rotational and vibrational motions.
3. Internal energy is the sum of all of the translational, rotational and vibrational kinetic energies of the particles and also any potential energy due to intermolecular forces.
4. Temperature is measured using degrees Celsius or Kelvins.
5. A Kelvin is a unit of temperature that is the same size as the degree Celsius, but with a zero point that is at absolute zero.
6. Theoretically, when all the available particle kinetic energy is removed from a system, its temperature is absolute zero: 0 K or -273 °C.
7. When two substances are in thermal contact, energy will naturally be transferred from the higher temperature substance to the lower temperature substance.
8. If no energy is transferred between objects in thermal contact, they are said to have the same temperature and to be in thermal equilibrium.
9. A thermometer always displays its own temperature. We use the zeroth law to infer the temperatures of other objects with which the thermometer is in contact and in thermal equilibrium.
10. If the objects have different temperatures, energy naturally flows between them, from the higher temperature object to the lower temperature object.
11. Energy that naturally flows between two objects of different temperatures is called heat.
12. The greater the difference between the temperatures of two objects in thermal contact, the greater the rate of flow of heat between them.
13. In general, when a substance increases its temperature, its particles can push each other apart, causing the object to expand or increase its volume.
14. Inside a solid, heat typically propagates through conduction. Conduction is a result of changes in the motions of particles due to collisions and interactions with other particles.
15. Inside a fluid, heat typically propagates through convection, which is the movement of a part of that fluid due to differences in gravitational attraction caused by differences in the densities of the parts of the fluid.
16. All objects that have a temperature above absolute zero transfer some energy through radiation -- electromagnetic waves that are emitted by energetic electrons losing energy.
17. As the temperature increases, both the amount and the energy that is radiated increase.
18. When heat flows to or from a system, the system gains or loses an amount of energy equal to the amount of heat transferred. This is the first law of thermodynamics -- the law of conservation of energy restated to include heat.
19. If heat is added to a system, it can cause the system to do external work or be stored as internal energy.
20. Different substances have differing abilities to store internal energy, called heat capacity.
21. Heat capacity can also be thought of as a sort of thermal inertia -- substances with a higher heat capacity resist changes to their temperature by requiring a larger energy transfer.
22. The total energy and work of a closed system is a constant.
23. Closed systems have minimal loss or gain of work or energy from their environments.
24. The useful energy in a system -- the energy that is available to do work -- naturally decreases over time.
25. Entropy is a measure of the disorder in a system.
26. Systems naturally progress toward states of maximum entropy.
27. Entropy in a system increases because it represents states that are significantly more likely than ordered states.
28. A system reaches equilibrium when it has achieved a state of maximal entropy.
29. At absolute zero, internal energy and entropy both approach a minimum.