Heat is an energy in transit, while temperature is a quantity that measures the amount of heat available for work in a system.
Temperature is related to the average kinetic energy of the molecules in the system.
Heat transfer
1. Conduction
2. Convection
3. Radiation
Heat always flows from hot to cold objects.
Thermal equilibrium is reached when the temperature of two objects in contact is the same.
Internal energy
The sum of all types of energies that particles exhibit, including kinetic energy and potential energy.
First law of thermodynamics
The change in internal energy of a system is equal to the energy transferred to or from the system that counts as heat minus the energy transferred to or from the system as work.
Isochoric process
When the volume is constant in the system, the change in internal energy will equal the heat transfer in and out of the system.
Isothermal process
When the temperature is constant, the heat transferred to the system will be used to do work.
Adiabatic process
When there is no heat transfer, the internal energy changes due to work on or by the surroundings.
Second law of thermodynamics
Heat will never flow from cold to hot, and no cyclic process can convert heat into work with 100% efficiency.
Entropy
The amount of disorderliness in a system that increases as usable energy decreases.
