Our Mini-Lakes Gone Wrong...

​With some careful reflection, students recognized that their fresh water models may actually be misrepresenting the ships in a field phenomena.  We noticed how rusty the boats were, and that specific metals rust more so in salt water than fresh, so we decided to add salt to our lakes to make our models more realistic and match the actual phenomena.

This also means we have to investigate what salt does to the water, since it's going to "throw" our data off.  With some carefully designing investigations, students recognized that salt can be crushed into smaller and smaller pieces, and over time, when added to water, can completely "disappear."  We gathered evidence to suggest that the salt was still in the water even though we couldn't see it because the volume of the water increased.  And all matter has both mass and volume!

This whole idea behind salt getting smaller and smaller is making us think about how water can get smaller and smaller.  Is it possible that water does this same thing?  And "disappear" like salt?  Does it go somewhere?

So over time, we saw the water droplets we sprayed on plastic cups disappear, and our hands inside the cups didn't get wet, so the water must have gone somewhere.  We're thinking that it went into the air, but we'll need to figure out a way to prove that!  

​Boy are we thinking!