When studying Egypt, or preparing for an extra spooky Halloween you might consider making a chicken mummy. To be honest, you don’t even need a reasonable unit to want to make a chicken mummy – they are fun and full of great science. I love all of the questions I get with the chicken mummy unit. Is it going to smell bad? Ew, I have to do what with the chicken? Why is the salt all wet? Creating your own mummy at home is a great opening to studying the process of osmosis.
Osmosis is when there are different concentrations of something in the water – for the mummies, and our osmosis experiments you can do at home, that is often salt. When you have an area that has a ton of salt (or sugar for our gummy bear experiment) the surrounding water is unhappy. It wants everything to be equal. Because of that water molecules will naturally flow from an area that has very little salt to an area that has a ton of salt. For the chicken mummy, this means water goes from inside the chicken (where there is little salt), to the bag full of salt (where there is…a ton of salt).
If you wanted to show osmosis in action relatively quickly you can put two gummy bears in cups, fill one cup with fresh water, and one cup with salt water. Ask yourself (and your students or kids) what do they think might happen? Is there an area that has a lot of salt or sugar? Is there an are that does not? In the case of fresh water, water will flow from outside the gummy in to try and make the two concentrations of sugar the same. This will make the gummy bear very large over the course of a day, or even overnight. Remember, this process of trying to even out concentrations is called osmosis. Play the video below to see what happens when you put a gummy bear in fresh water overnight!
If you want even faster results, you can put slices of a potato in salt water and in fresh water. Again, ask yourself (and your students or kids), what do you think will happen? Remember, there are a few salts in the potato itself. Once you have thought about it, go ahead and slice up a potato to try the experiment for yourself, then check your answers with our results below! I hope you enjoyed our two quick experiments that can help students understand osmosis in a hands-on inquiry fashion!
Which potato slice has been in salt water? Which one has been in fresh water?
Play the videos below to find out what happens!