Which is the least reactive element on the periodic table?

Neon is the least reactive element on the periodic table. As a noble gas, neon is colorless and odorless with extremely low reactivity in its natural state. Neon has an atomic number of 10.

Neon is considered the most noble of the gases, as it has the lowest reactivity in a group of elements with low reactivity. Elements react with each other to form groups of eight valence electrons. Neon has eight stable electrons in its natural state, so it has no reason to seek out electrons from other elements. Neon can be made to react artificially with fluorine under controlled laboratory settings.