If salt is left behind during evaporation, how would the salt deposits appear above the original water line?
Answer Hi Mr. K — Don’t worry, your interpretation of physics is OK. The salt is not evaporating. You likely have 2 things going on here. The salt crystals on the high window are likely from when you filled the containers. If a small amount of salt water was spilled, it might not have been visible as it spread out, and this would evaporate more quickly because of the increased surface area to volume, compared to the main bulk of the liquid. That’s a likely explanation of the crystals just above the marked water line, too, from filling or moving the containers and sloshing salt water up there. But there could be something else going on on the last one — surface tension and the meniscus of the water. As you know, the water surface in the container is NOT flat, it’s curved, and is being pulled up the sides of the container by capillary action. As the water evaporates from this thin layer above the main water surface, it’s actually pulling addtional salty water up there, increasing the s
