Water’s boiling temperature is 100C or 212F, when you spill some on concrete or leave a cup of water outside, it disappears without it reaching 100C even if it is in the shade. The water from the ocean also evaporates, but it is not boiling. This happens with other liquids to such as isopropyl alcohol, or gasoline.
How does this happen?
In: Chemistry
Liquids are made of molecules.
The “temperature” of a liquid is the average “speed” (more or less) that all the molecules are moving at.
This “speed” is actually a bell curve. The majority of the molecules in rhe liquid are moving around that speed, but a bunch are moving slower, and a bunch are moving faster.
“Boiling” isn’t actually about temperature, it’s about speed – it’s the speed that molecules need to be at, to leave the liquid altogether. Below that “speed”, something called “surface tension” pulls the molecules back. Imagine that all the molecules are something like magnetic and pulling on each other, but if you’re going fast enough, and there aren’t other molecules in the way, you can break free of the pull.
Once a liquid reaches it’s “boiling point”, the majority of the liquid’s molecules are moving fast enough to leave the liquid. But below that temperature, SOME of the molecules are moving fast enough to leave. If a molecule happens to be near the surface while it’s moving that fast… It leaves!
And that’s evaporation.
Incidentally this is also why boiling happens at different temperatures based on air pressure – higher air pressure means that more air molecules “get in the way” of a molecule leaving the water (again, more or less), even though there aren’t any actual water molecules “in the way”.
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