Physics · Glossary

What is The six changes of state?

Also known as: melting · solidification · vaporization · condensation · sublimation

Definition 39.1 Primary & Middle School Physics · Chapter 39 — Water in All Its States

Between its three states, water has six doors, each with its scientific name:

  1. solid \to liquid: melting; liquid \to solid: solidification (freezing);
  2. liquid \to gas: vaporization — roaring fast at the boil, quiet and cool as evaporation; gas \to liquid: condensation;
  3. solid \to gas directly: sublimation, and gas \to solid directly — rarer doors, but real: frost feathers on a freezing window grow straight from invisible vapor, skipping the liquid entirely.
Water’s six doors, with their proper names. Warmth drives the red doors; cold drives the blue.
Water’s six doors, with their proper names. Warmth drives the red doors; cold drives the blue.

Examples

Example 39.2 (Doors all around you)

Morning frost melting off the grass; laundry evaporating on the line; a cold mirror condensing your shower’s vapor; the freezer solidifying tomorrow’s ice cubes; frost feathers grown overnight on the pane. One substance, six doors, all within a day of ordinary life — name them and you own them.

Example 39.9 (The great round trip, with vocabulary)

The childhood story of sea, cloud and rain now reads like a ledger. The Sun’s warmth drives vaporization from the seas — tonnes upon tonnes rise invisibly. High and cold, the vapor condenses into cloud droplets; colder still, droplets freeze into snow. Snow piles into glaciers; glaciers melt into rivers; rivers return every gram to the sea. Around the whole circuit, Proposition 39.4 holds: the planet neither gains nor loses a drop — the water in your glass has sailed this loop since before the dinosaurs.

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