水蒸気

1. Origins, structure, and basic meaning

• Structure: 水蒸気 is read as すいじょうき and is a noun for water vapor, water in its gaseous state.
• Basic usage: Vapor from a pot clouding a window appears in 水蒸気で窓が曇る, while vapor becoming droplets on a cold plate appears in 水蒸気が水滴になる.

2. Common pitfalls and similar expressions

• It can condense into droplets when cooled
  • Water vapor in the air forms small droplets when it reaches a cold surface and condenses.
• Difference from 湯気
  • Unlike the everyday word for the visible mist rising from hot water or food, this term broadly denotes water in the gaseous state.