Scientists have observed a never-before-seen form of oxygen, and its behavior could call into question what nuclear physics ...

But what makes oxygen different from carbon? It is the number of protons in the nucleus of an atom that is the defining feature of the atom. It's what makes one element different from another.

When two hydrogen atoms and an oxygen atom get close enough, the electron from each atom feels an attraction from the protons in the other atom's nucleus. This attraction pulls the atoms together. The ...