While our microscope tests told us that there was still stuff in the water, it was hard to tell what was what in our samples. This got us thinking about isolating individual items that we knew went into the water, but that we weren't really sure if they were there (not even the microscope could reveal with the highest magnification). Students were convinced that this stuff was still there, so we agreed more tests should be done to prove stuff was in the water (and some of our water samples with isolated stuff in them looked like regular water).
Here's what we came up with:
1. Do a water level test--we noticed that the water level kept rising with the dirty water we made, so if the water level rose when we put just ONE thing in, it should rise, too, proving the substance is still there even if we can't see it.
2. Do a weight test--we know that each of the substances weighs something, so if we add it to water, then the water should increase in weight even if we don't see it.
3. Do a taste test--yes! you read that right! Some of the substances are safe to taste, so hopefully we can still taste it when it is in water!
4. Do an evaporation test--let the water + whatever we add to it sit out in our classroom and let the water evaporate. Hopefully if the water evaporates, then whatever is still in the water will stay behind!
We hit the ground running today! Here's a glimpse at a student notebook for how we organized our data collection based on the student tests they wanted to investigate.
Here's what we came up with:
1. Do a water level test--we noticed that the water level kept rising with the dirty water we made, so if the water level rose when we put just ONE thing in, it should rise, too, proving the substance is still there even if we can't see it.
2. Do a weight test--we know that each of the substances weighs something, so if we add it to water, then the water should increase in weight even if we don't see it.
3. Do a taste test--yes! you read that right! Some of the substances are safe to taste, so hopefully we can still taste it when it is in water!
4. Do an evaporation test--let the water + whatever we add to it sit out in our classroom and let the water evaporate. Hopefully if the water evaporates, then whatever is still in the water will stay behind!
We hit the ground running today! Here's a glimpse at a student notebook for how we organized our data collection based on the student tests they wanted to investigate.
We had a quick discussion at the end of class today thinking about what these new tests meant. While we were really certain our microscopes would give us the evidence we thought we were looking for, it seemed as if our zoom-ins didn't really tell us much. Tasting, weighing, marking the level, and hopefully evaporating the water will give us a better picture of what happens when things enter our water. It'll hopefully also help us better understand how they get this stuff out!