The distribution of outermost shell electrons, known as valence electrons, of organic molecules was observed for the first time. As the interactions between atoms are governed by the valence electrons ...

A ‘hole’ arises due to a missing electron in the valence band, which normally participates in covalent bonding between atoms. The absence of an electron creates a local absence of a negative charge, ...

When two hydrogen atoms get close enough, the electron from each atom feels an attraction from the proton in the other atom's nucleus. This attraction pulls the atoms together. The electrons end up ...