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In our class discussion we hypothesized that the smaller molecules would move more quickly, therefore moving longer distances in a controlled amount of time and the bigger molecules would move more slowly and therefore shorter distances.

In our investigation we gathered results that support our collective hypothesis. For each bead size we ran 2 trials for 30 seconds. We then calculated the averages for each size. The results are as follows:

WARNING: THE IMAGES THAT FOLLOW MIGHT BE GRAPHIC AND ARE NOT SUITABLE FOR YOUNG CHILDREN.

2 microns: 34

4 microns: 26

8 microns: um, like...nothing. maybe 2.3.

source: http://www.ppo.dk/gifs/sort2&5.gif

In the second experiment, we tried to figure out why cell membrane moved away from the cell wall when NaCl was added and then why it moved back when water was added. Our story is that the NaCl opened the membrane so that the water could escape and since molecules are always moving the water left the cells and moved out to the paper towel because it was attracted to itself. It's so vain, it probably thinks this experiment is about it...

When we added the water back, the cell membrane expanded and moved out towards the cell wall. Molecules were moving so fast that the water didn't have a chance to move out once it got in.