Final answer:
A system strives to minimize its total energy due to the principles of thermodynamics, where systems naturally move towards lower energy states. Energy is conserved in isolated systems, but during energy transfers, some energy becomes unusable as waste heat, increasing entropy as per the second law of thermodynamics.
Step-by-step explanation:
A system likes to minimize its total energy because this is a natural tendency governed by the laws of thermodynamics. The tendency of all systems, chemical or otherwise, is to move toward the state with the lowest possible energy. The total energy of a system, a combination of kinetic and gravitational potential energy, is preserved in an isolated system.
Living systems, for example, are highly ordered and require constant energy to maintain a state of low entropy. However, in doing so, no process is completely efficient, and some usable energy is always lost as waste heat, increasing the entropy of the system's surroundings. This is in line with the second law of thermodynamics, which states that all energy transfers increase the entropy of the universe, indicating that systems evolve in ways that are consistent with energy conservation.