The least reactive elements on the periodic table are the noble gases, which are found in Group 18 (or Group 0) of the periodic table. These gases include:
- Helium (He)
- Neon (Ne)
- Argon (Ar)
- Krypton (Kr)
- Xenon (Xe)
- Radon (Rn)
Noble gases have a complete valence shell of electrons, which makes them very stable and generally unreactive under normal conditions. They do not readily form chemical bonds with other elements, which is why they are considered to be the least reactive elements on the periodic table.