What defines a sea? What can you hear when you are close to the sea? What is the sea like? What does it feel like? Have you ever tasted seawater? What does it taste like?

A sea is a smaller part of an ocean and is partially contained by an area of land.

Have you been wondering why the ocean is salty? Why do you think the ocean is salty? 

Watch a video:

Have fun with this experiment 'Floating egg'

Try to answer these questions:

What happens?

Why do you think it happened?

What would have happened if you added even more salt?

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 10 g salt 100 g of water, the total mass is now 110 g. 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.

Can we drink sea water? Why not?

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