What makes eggs float in saltwater

As I began preparing for this lesson, I was a little more nervous than I usually am. I think I was just nervous about the I-CM. I was scared that my students were not going to talk about their investigations because they were not accustomed to this type of method.

My main concern was that the students were not going to understand and discover the main concepts of the lesson. I really underestimated the knowledge of my students. I performed the experiment ahead of time, and everything worked out perfectly. Now, it was time to see if my students could get it to work out perfectly.

There was one aspect of this lesson that I felt extremely confident about and that was my preparation. I wrote out everything that I planned to do for the lesson. I knew exactly what I was going to say. I tested all of the materials before hand, including every single boiled egg and every drop of salt water.

I did not want to chance anything going wrong with my preparation. I went ahead and assigned the different groups ahead of time so I could separate the children that I felt may cause a disturbance. If I were to do this lesson again, I would have smaller groups maybe groups of 2 or 3 because the materials are inexpensive.

As I introduced the lesson, the students seemed very anxious. I had already placed the materials on their desk so they were very curious about the experiment. I was a little hesitant about placing the materials on their desk ahead of time, but everything worked out fine. I knew the class well enough to trust them. I introduced each material on their desk so there would be no question after the investigation had begun.

We went through each prediction question together and I allowed them time to make predictions within their groups. If I were to do this activity again, I would let each child have their own sheet to record their observations and predictions on. After all predictions were made, I let the experimenting begin. I encouraged the students to talk with their group members about any questions they had. As they performed the experiment, they were to write their observations on the sheet provided.

While the children were investigating, I walked around to see what each group was discovering. During our colloquium, the students talked about all of the observations they recorded. I am so glad the experiment worked correctly for all groups because they all had the same observations. Next time, I would write their observations on the board to make what they say seem a little more important. Because the salt is denser than the water, the salt will sink. When you drop the egg into the water, it will sink through the plain water until it reaches the saltwater at the bottom of the glass.

The density of the saltwater prevents the egg from sinking any lower, so the egg will float in the middle of the glass. Angela Powell Watson has written for dozens of print and online resources, and recently published her first book.

Third Grade Science for the Measurement of Density. Science Project on How to Float an Egg. How to Calculate the Density of a Solution. Osmosis Egg Experiments. Brine Vs. Density is the mass of a material per unit volume. For example, the density of freshwater under standard conditions is approximately one gram per cubic centimeter. But, if you add enough salt to the water, the egg will actually float back up to the surface!

Adding salt to the water increases the density of the solution because the salt increases the mass without changing the volume very much. When enough salt is added to the water, the saltwater solution's density becomes higher than the egg's, so the egg will then float!

The ability of something, like the egg, to float in water or some other liquid is known as buoyancy. But just how much salt is needed to make an egg float? In this science activity you'll figure that out by making solutions with varying concentrations of salt in them. Observations and results Did the egg float in cup 1 and 2, but not in cups 3, 4 or 5? You likely saw that the egg floated best in cup 1, floated a little less in cup 2 but part of it was above the surface and did not float in the other cups.

Cup 1 had the undiluted salty solution that you originally prepared, which was one half cup of salt in two and one half cups water total. The concentrations of the salt solutions in cups 2 to 4 were halved as you increased in cup number; for example, the concentration of the salt in cup 2 was half that of cup 1, and the concentration of the salt in cup 3 was half again of cup 2. Cup 5 had plain tap water. The egg should have sunk in cups 3, 4 and 5 because the density of the egg was higher than the density of the solutions or plain tap water in those cups.

Cups 1 and 2 had more salt in them than the other cups with cup 1 having the most salt , which means these solutions were denser.