Dear student, Atom is basic unit of matter. It has electrons, protons and neutrons. Neon, Helium exist as Ne and He respectively i .e. in atomic form. An element is a substance which is made of one type of atoms containing same number of electrons and protons. Like hydrogen atom contains 1 electron and 1 proton. So, hydrogen element is made of same atoms which have 1 electron and 1 proton. All the atoms have the same chemical properties. Elements cannot be broken down into a simpler substance. Likewise, one element cannot be chemically converted into a different element. Chemical elements are the simplest of substances. Regards