If the transfer integral of these particles is small, the repulsion between them can lead to the Mott transition. If these particles are “nearly free” (10[1])but weakly interact with a periodic potential, Bloch’s theorem can be used to compute their band structure. (10[1])Superconductivity is caused (-5[1])by bound pairs of these (10[1])particles (10[2])theorized by Leon Cooper. Places in a lattice where these particles don’t exist are called (10[1])holes. (10[1])If (10[1])a photon’s energy exceeds a material’s work function, it can eject one of these (10[2])particles in an effect whose description won Albert Einstein the Nobel Prize. For 10 points, name these negatively-charged particles whose orbitals surround the nuclei of atoms. ■END■ (10[1])