Have you ever thought about what you and everything around you are made up of? In this film we will take a closer look at the smallest elements on Earth, atoms and elementary particles. You will learn that everything in existence is made up of atoms, and that the atoms consist of elementary particles: positively charged protons, negatively charged electrons, and uncharged neutrons. You will also get to know that the electrons in the outermost electron shell are called valence electrons, and that atoms that are charged are called ions. Finally, you will learn that isotopes are atoms of the same element, but which vary in weight.