Why is H2O called hydrogen dioxide

Water - what is it?

You drink water, you wash in water, and you can swim in the water. Water is important for all living things.

Water doesn't taste good. It doesn't smell and it's see-through. But what exactly is water?

Water is a substance. All substances consist of the smallest particles.

These particles are called atoms. You can't see atoms because they're very, very small.

Water is also made up of atoms.

Water is made up of two different atoms: the hydrogen atom and the oxygen atom.

So water is a molecule. Because molecules always consist of two or more atoms.

The chemical formula for water is called H2O. The water molecule has two hydrogen atoms (H) and one oxygen atom (O).

That is why the formula for water is called H2O.

By the way:

How big is an atom in terms of numbers?

An atom is 0.1 nanometers in diameter. That is 0.0000000001 meters.

You can see atoms if you have a very special microscope. For example the scanning tunneling microscope.

The German physicist Gerd Binnig invented the microscope. For this he received the Nobel Prize in Physics in 1986.

This is a model of the water molecule.

It consists of one oxygen atom and two hydrogen atoms.

The hydrogen atoms are slightly positively charged. The oxygen atom is slightly negatively charged.

The atoms attract each other like a magnet.

Do you know that?

Click the correct answer.