The element with the maximum number of atoms in its molecular form is Sulfur (S), with 8 atoms per molecule in S8S_8S8 .
Sulfur (S8) forms a stable cyclic molecule with eight atoms, which provides a lower energy state and greater stability at ordinary temperatures.
In contrast, oxygen (O2) exists as a diatomic molecule, which is also stable but has a different bonding arrangement that allows it to remain gaseous at these temperatures.
