Final answer:
The term 'law of conservation of energy' describes the principle that the total amount of energy in an isolated system remains constant, although it can change forms or be transferred within the system.
Step-by-step explanation:
The term that matches the definition 'energy is conserved with every process' is the law of conservation of energy. This fundamental principle in physics states that the total amount of energy remains constant in an isolated system, regardless of whatever processes occur within it. This means that energy can neither be created nor destroyed; it can only change in form or be transferred from one part of the system to another. Hence, mechanical energy, metabolic rates, and even nuclear energy are all subjected to this law. The conservation of energy is an empirical fact based on countless experiments, and despite the discovery of new forms of energy, this law has consistently applied.
For example, in a closed system, when a ball is dropped from a height, its potential energy is converted to kinetic energy as it falls, but the sum of the potential and kinetic energy remains constant. An understanding of the conservation of energy allows for analyzing physical processes and predicting outcomes without knowledge of the intermediate steps, which can be useful in various areas of engineering, science, and technological development.