What happens to the entropy of a system as heat is added?

When heat is added to a system, the entropy typically increases. Entropy is a measure of the disorder or randomness of a system, and adding heat tends to raise the temperature of the system, which increases the molecular motion. As the molecules become more energetic and move more vigorously, the number of available microstates for the system increases, leading to greater disorder.

This aligns with the second law of thermodynamics, which states that in an isolated system, the total entropy can never decrease over time. In most practical scenarios involving the transfer of heat into a system, the additional energy contributes to a greater distribution of energy among the molecules, thereby increasing the overall entropy.

Therefore, adding heat to a system generally results in an increase in entropy, making the correct answer to the question about the effects of adding heat on entropy clearly evident.