> In the natural world, evaporation occurs when sunlight warms the surface of the Earth, breaking the bonds which hold water molecules together.
Which is... sort of not inaccurate, but feels like it implies a misleading concept, and makes me think the author copied it without understanding it.
I am very skeptical how much usable power could be generated using the 'drinking bird' approach. Show me the engine or generator that the drinking bird powers . . .
Really? Do puddles not dry up at night?
My impression was that evaporation occurs because that's just the way liquid behaves. It's more important that water molecules are really small than that they experience sunlight. Temperature-based evaporation is "boiling", and sunlight doesn't make a meaningful difference there, as far as water goes...?
1) Breaking the covalent bonds that hold individual water molecules together, preventing them from splitting into two hydrogen and one oxygen atom. That's clearly not true.
2) Breaking the hydrogen bonds that stick one water molecule to another, keeping the water in liquid form. That's true.
In any case, it's poorly phrased.
Cooking oil, notably, will not evaporate the way water will -- if you spill it somewhere, the oil will mostly just stay wherever you left it until you clean it up -- but my understanding was that this is because oil molecules are huge and heavy while water molecules are tiny.
That's almost worse than the original! :)
Water evaporates because their energy (heat) causes the molecules to bounce around and sometimes escape the cohesive attraction of their friends and into the air. More energy, more evaporation.
This works well with small water molecules, less well with larger and heavier liquids.
Hmm, could you call this mysterious "cohesive attraction"
> the bonds which hold water molecules together.
...? If not, then please do describe this cohesive attraction.
I've come to realize some people just like to complain on the internet.
Evaporation does not break those bonds, it's just the intact molecules energetically escaping the surface tension of the liquid.
(Disclaimer: My high school chemistry books have not left their shelves in many years, except when moving.)
Surface tension is a bond that binds water mold together similar to how mortar holds bricks together in a wall.
Mortar doesn't make the brick solid, but it holds the bricks together.
People are reading bond in two different ways. Bond within a molecule vs bond between molecules.
1. https://www.usgs.gov/media/images/surface-tension-forms-a-st...
I don't think that's true for naming, but regardless warmer water evaporates quicker.
And the statement doesn't say evaporation doesn't occur for other reasons, though the wording feels like it implies it.