Entropy is a measure of disorder or randomness in a system.
- The more spread out and disorganized the particles and their energy are, the higher the entropy.
- The more ordered and fixed the arrangement, the lower the entropy.
Key points:
- Solids → have low entropy (particles are tightly packed, ordered).
- Liquids → have higher entropy than solids (particles move more freely).
- Gases → have the highest entropy (particles move randomly in all directions).
Everyday examples:
- Ice melting → solid turns into liquid → entropy increases.
- Sugar dissolving in water → molecules spread out in solution → entropy increases.
- Perfume spreading in a room → gas molecules move freely everywhere → entropy increases.
In short: Entropy tells us how energy and matter are spread out. Nature tends to favor processes that increase entropy, because they are more likely to happen on their own.