According to the Second Law of Thermodynamics, what happens to the entropy of an isolated system during a spontaneous change?

In accordance with the Second Law of Thermodynamics, during a spontaneous change, the entropy of an isolated system increases. Entropy, a measure of disorder or randomness in a system, tends to increase because spontaneous processes naturally move toward a state of greater disorder. Essentially, as systems evolve, they explore a wider range of possible configurations, which results in a higher level of entropy.

This increase in entropy reflects the natural tendency for systems to evolve toward thermodynamic equilibrium, where the arrangement of energy and matter is maximized in its dispersion. In an isolated system, which does not exchange energy or matter with its surroundings, the only way for it to achieve a new equilibrium state is through an increase in entropy.

Other options suggest different scenarios: stating that entropy remains constant would imply a reversible process, which is not consistent with spontaneity. A decrease in entropy contradicts the principle of spontaneous processes moving toward greater disorder, and the notion that entropy can either increase or decrease does not align with the deterministic nature of spontaneous changes in isolated systems. Hence, the increase in entropy during spontaneous changes is a fundamental concept in thermodynamics that reinforces the natural progression towards equilibrium.