Which statement describes high entropy?

• A. More disorder.
• B. More order.
• C. Entropy is independent of disorder.
• D. Entropy is zero.

Answer: (A)

Entropy measures how spread out energy and matter are, or how many microscopic configurations a system can have. When there are many possible arrangements, the system is more disordered, and entropy is high. For example, a gas has molecules moving freely in lots of possible positions and speeds, giving a huge number of microstates and thus high entropy. A highly ordered crystal, by contrast, has far fewer possible configurations, so its entropy is low.

Therefore, high entropy is described by more disorder. The other statements don’t fit: more order describes low entropy; entropy isn’t independent of disorder; entropy isn’t always zero (that’s only a special case at absolute zero for a perfect crystal).