Over the next couple of weeks we are going to have a go at some under the sea science experiments. This week we are going to try the floating egg. You will need 2 eggs, some salt and water. Download the document below and have a go. Talk about the experiment with your child and predict what will happen.
What do you think will happen if we put an egg in a bowl of water? Why do you think that? What happens?
What do you think will happen if we stir a spoonful of salt into the bowl of water and then add the egg? Why do you think that will happen? How many spoonfuls of salt did you add to make the egg float?
Draw a picture and label it. You could write a sentence to say what happens.
The Science Behind the Experiment – A Guide for Adults
Objects float better in salt water than in fresh water because salt adds mass to water and makes it denser. If you add 10g of salt to 100g of water, the total mass is now 110g. This increase in density causes objects to float better on the surface. The denser the water, the easier it is for objects to float on top.
To make the egg float it takes approximately 4 tablespoons of salt per litre of water.