In chemical terms, a single element is composed of only one type of atom, and cannot be broken down any further into its sub-atomic parts. All the types of elements we are aware of are ordered by their atomic number in the periodic table; this can help to demonstrate trends of elements with similar chemical properties also in their group (a vertical column) or period (a horizontal row).
An example of an extremely abundant element is hydrogen (H). Hydrogen is the first element in the periodic table, with one electron and one proton in its nucleus; however, it contains no neutrons. This means that its electronic configuration is 1s1.