Atoms are the building blocks of matter. They are everywhere from your shoes to the water that you drink. They are very small, so small that they are not visible to the naked eye. Atoms are made out of three main particles: Neutrons, Protons and Electrons. These particles are very important and give the atom its properties.





In an atom you have a nucleus which consists of protons and neutrons. Around the nucleus you have electrons which whizz around the nucleus. The electrons are arranged in shells or energy levels around the Nucleus. For the first 20 elements the lowest energy levels are filled first. Only a certain number of electrons are allowed in each shell. The first shell has 2 electrons, the second shell has 8 electrons and the third shell has 8 electrons.



