Heat is the transfer of thermal energy from one object to another, while temperature is a measure of the average kinetic energy of the particles in a substance. In other words, heat is the energy being transferred, while temperature is a measure of the intensity of that energy.
The first law of thermodynamics, also known as the law of conservation of energy, states that energy cannot be created or destroyed, only transferred or converted from one form to another. This means that the total energy in a closed system remains constant.
An open system is one that allows energy and matter to be exchanged with its surroundings, while a closed system does not allow for the exchange of matter, but can exchange energy with its surroundings. In thermodynamics, closed systems are often used to analyze the flow of energy.
Entropy is a measure of the disorder or randomness in a system. In thermodynamics, it is often referred to as the measure of the unavailable energy in a system. The second law of thermodynamics states that the total entropy of a closed system will always increase over time.
Enthalpy is a measure of the total energy of a system, including both its internal energy and the energy required to push back the surrounding pressure. It is often used in thermodynamics to analyze systems at constant pressure, such as in chemical reactions or phase changes.