What will sink then float in 30 seconds

Make sure all of the items you pick can get wet! Look at the objects you collected. Draw a picture of each one in the boxes on the left side of the worksheet. Make a prediction about each object — do you think it will sink or float in the tub of water? To make a prediction means to say what you think will happen. Mark your prediction on the worksheet for each item circle float or sink. Drop the objects into the water one at a time. Watch what happens to each one.

Did you predict correctly? Even though some of your items seemed very light things like a paperclip or a button , they still sank in the water. Some objects that might have seemed sort of heavy like a wooden block probably floated. It also depends on its density. Density is a measure of how solid something is. All things are made up of tiny particles called molecules. If the molecules inside an object are very close together, the item is solid, or dense.

If the molecules are farther away from each other, the object is less dense, or less solid. An example of a very dense item is a penny. A cork is less dense. A penny, paperclip, or button sank because the materials they are made of metal for a paperclip and penny, plastic for a button had more density than water. Their molecules are closer together than water molecules are. A cork, piece of wood, or Styrofoam floated because those materials have less density than water.

All the objects that were less dense than water floated in the water! Objects that were more dense than the water sank. Do you know why oil floats on water? Would an object that sinks in oil be able to float in water? Try this experiment to find out and learn more about density. Add 2 or 3 drops of food coloring. Watch what happens.

The layers should separate so that the corn syrup is on the bottom, the oil is on top, and the water is in the middle. Guess where each of your objects will land when dropped into the cup, then test them out one at a time.

The corn syrup was the most dense liquid, so it sank to the bottom of the cup. The water was less dense than the corn syrup, but more dense than the oil, so it settled on top of the corn syrup. Find more Egg Experiments For Kids here! You only need a few simple ingredients for this experiment and it is easy and safe enough to do with your kids at home too! This post may contain affiliate links. As an Amazon Associate, I earn from qualifying purchases. Glass or plastic cups work great for this, but just make sure the cup is clear so that you can see what is going on inside!

Now gently set an egg into the water-filled cup and pay attention to what the egg does! Do you think it will float to the bottom of the cup or float to the top of the water!? As long as you use an egg that is fresh bought from the store within a week or two, or fresh off the farm , then the egg should sink to the bottom of the cup. We have now learned that an egg will sink in water, but what will happen if we change the density of the water by adding some salt to it?

Do this by filling the cup just a little more than halfway with water. Then pour a generous amount tablespoons of salt into the water and stir it with a spoon until the salt dissolves into the water. This will take about 30 seconds of stirring. You will know the salt is dissolved when the water changes from foggy looking, to becoming clear again. Grab an egg and gently place it into the cup of salt water. Do you think the egg will still sink to the bottom like it did in the freshwater, or will it float in the saltwater?

As long as you added a generous amount of salt, the egg should remain floating at the top of the saltwater with a portion of the egg poking out of the water! Now that we have discovered an egg will float in salt water and sink in freshwater, what do you think will happen if we do the same thing, but mix less salt into the water this time?

Give it a try by again filling a third cup a little more than halfway with water. Then add only a tablespoon or so a salt to the water this time. Mix it with a spoon until it is all dissolved. The hope is that with a much more diluted solution of saltwater this time, we can find a perfect balance between the density of the water and the egg to make it neither sink or float and stay suspended in the middle of the cup.

Watch very closely what happens to the egg. Does the egg slowly sink to the bottom or slowly rise to the top? Or does it do exactly what we were wanting and stay hovering right in the middle of the cup without sinking or floating? Getting the density of the water just perfect enough to make the egg hover depends on the ratio between the amount of water in your cup and the amount of salt in the water. It might take a little bit of trial and error by adding a little more water or a little more salt to get the perfect mixture, but eventually you should be able to get the water to the same density as the egg and make the egg hover!