SEARCH Articles Figures Tables Electron Configurations How Electrons Occupy Orbitals Electron orbitals Electron, orbiting Electrons occupy atomic orbitals Electrons occupying orbitals Electrons occupying orbitals Free-electron model highest occupied molecular orbital Highest occupied molecular orbital electron injection Highest occupied molecular orbital, unpaired electron Highest occupied molecular orbitals HOMOs). electron promotion Occupied orbital Occupied orbitals Orbital electrons Singly occupied molecular orbital single electron transfer oxidation