|MadSci Network: Other|
What a great question, Jaimie! There are a couple reasons why wet sponges soak up more water than dry sponges. The first one has to do with the sponge. It's made with tons of tiny holes. When the sponge is dry and water flows into it, a lot of the water escapes through these holes. As the sponge gets more wet, it swells from all the water it is taking in, and a lot of those holes get filled up, so not as much water can escape. The second reason has to do with water itself. Water is very sticky stuff, that's why you have to dry your hands after you wash them, because there's still water sticking to them. Water molecules stick especially well to other water molecules, because they're highly attracted to one another. This means that if a sponge is already wet, the water in the sponge will grab hold of the water being poured into it, so the sponge absorbs more water. Another interesting thing about sponges is that different kinds of sponges absorb different amounts of water. For more info on this, check out this website: howthingswork.virginia.edu
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