Science Experiment for Kids- Floating or Sinking Eggs

It is egg experiment time at my house. Maybe it is Easter and the desire to dye eggs that lead us down the path of experimenting with eggs. This is the first of a series of posts on science experiments for kids that focuses on eggs. Each experiment we do will have a printable instruction/ recording sheet.

This particular experiment tests out whether adding salt to a glass of water will help the egg float or if it will sink to the bottom. That is why we called this science experiment for kids Egg Experiment: Sinking or Floating Eggs.

We started the experiment by gathering together the materials list on the instruction sheet. It didn’t take long there are only four items needed to do this experiment.

Here is what we did:

• We added warm water to tall clear drinking glass. ( You could use a clear jar or bowl in place of a glass.) We went with tall glass to make sure that we would be able to easily see the egg floating if it did indeed float. Having a lot of water in the glass would help us do that.

• We then carefully placed the uncooked eggs in the glasses. We were careful for two reasons. The first reason was that the eggs were uncooked. The second reason was that we didn’t want to displace too much water. (Yes, this turned into a lesson on how objects like hands take up space and can push water up.)

• The egg in the unsalty water floated to the bottom and sat there. The egg placed in the salty water bobbed a little and then hung in the water. It just floated happily in the cup.

• We took time to talk about how the salt had changed the water and why this change made the egg float. We each tried to tap the egg and see if tapping it would cause it to descend into the water. The egg went down a little, but then it rose again.

• Why not add some of the salt water to the clear water glass we decided. Some of the clear water was poured from the clear water glass and we replaced it with some of the salty water. (I had read this might work.) It didn’t make the egg in the clear glass start floating.

We were left with several questions when we finished this activity.

• If we added more salt to the salty glass, would the egg float higher?
• If we had more salt in the salty glass then added that water to the clear glass, would the egg have floated?
• Would a cooked egg float if placed in salt water?

These questions will be answered on another day.  Instead of exploring them we decided to work on the bottom of the activity sheet instead. JDaniel and I composed a sentence orally describing the activity and he wrote it down. Then he drew a picture illustrating what had happened during the experiment.