How is a water molecule built up?
A water molecule consists of three atoms; an oxygen atom and two hydrogen atoms, which are bond together like little magnets. The atoms consist of matter that has a nucleus in the centre. The difference between atoms is expressed by atomic numbers. The atomic number of an atom depends on the number of protons in the nucleus of the atom. Protons are small positively charged particles. Hydrogen has one proton in the nucleus and oxygen has eight. There are also uncharged particles in the nucleus, called neutrons. Next to protons and neutrons, atoms also consist of negatively charged electrons, which can be found in the electron cloud around the nucleus. The number of electrons in an atom equals the number of protons in the nucleus. The attraction between the protons and electrons is what keeps an atom together.
