Entropy decreases when which changes occur?

Entropy decreases when which changes occur?

• A. Temperature decreases; Volume decreases; Number of particles decreases
• B. Temperature increases; Volume decreases; Number of particles decreases
• C. Temperature increases; Volume increases; Number of particles increases
• D. Temperature decreases; Volume increases; Number of particles decreases

Answer: (A)

Entropy measures the number of ways particles can be arranged and distributed among energy levels for a given energy, volume, and particle count. Lowering temperature reduces the population of higher-energy states, narrowing the energy distribution and decreasing the number of accessible microstates. Reducing the volume confines particles to a smaller space, limiting their possible positions and momentum states, which lowers the number of microstates. Fewer particles remove many possible arrangements, also shrinking the total count of microstates. When all three of these factors decrease, the overall number of accessible microstates drops, so entropy decreases. Increasing any of these factors would tend to increase entropy because more microstates become available.

Entropy measures the number of ways particles can be arranged and distributed among energy levels for a given energy, volume, and particle count. Lowering temperature reduces the population of higher-energy states, narrowing the energy distribution and decreasing the number of accessible microstates. Reducing the volume confines particles to a smaller space, limiting their possible positions and momentum states, which lowers the number of microstates. Fewer particles remove many possible arrangements, also shrinking the total count of microstates. When all three of these factors decrease, the overall number of accessible microstates drops, so entropy decreases. Increasing any of these factors would tend to increase entropy because more microstates become available.