The element that is non-reactive due to its stable configuration and high atomic number is helium (He). Helium is located in the noble gases group on the periodic table. It has an atomic number of 2, which means it has two protons in its nucleus. Helium possesses a stable configuration with a filled valence electron shell containing two electrons. This full electron shell provides helium with exceptional stability and makes it highly non-reactive under normal conditions. Helium does not readily form chemical bonds with other elements, which is why it is often referred to as an inert gas.