The Shrinking Egg

Materials:

2 Ziploc sandwich bags
clear corn syrup
raw, shell-less egg (dissolve the shell by soaking the egg in vinegar for 48 hours before the experiment)
1 glass

Directions:

1) Fill the Ziploc bag about half-full of corn syrup.
2) Place the egg in the bag. It will float, so don't be surprised. Take careful note of the size of the egg, then place it in the glass.
3) Check the egg in a few hours, then again the next morning. Did it look bigger or smaller? Let the egg sit for 3 days, by now you should see a size difference.
4) Remove the egg from the corn syrup, and gently wash it. The egg should look shrivelled, and you can feel the yolk.
5) Half-fill another Ziploc bag with water, and put the egg in it. Let it sit supported by the glass for a few days. Are you surprised to see it back to normal?

Explanation: This experiment shows osmosis. Osmosis is the movement of water through cells. The water flows from where there is water to where there isn't, so the water went out of the egg and into the corn syrup. The corn syrup could not go into the egg, so the egg looked shrivelled. When you put the egg into the bag of water, the water could move in and out freely. The membrane acts as a filter, with tiny hole that let the water in and out, but corn syrup and other things can't get through.


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