History of fundamental quantum concepts-three periods. Period 1 o Planck- finite grains of energy in emitting and absorbing radiation, and the constant h bearing his name o Einstein-notion of quantum of light (photon as named much later) o Bohr-quantized, permitted orbits and quantum jumps for atomsHistory of fundamental quantum concepts – three periods. Period 1. ⚫ Planck – finite grains of energy in emitting and absorbing radiation, and the constant h bearing his name. ⚫ Einstein – notion of quantum of light (photon as named much later). ⚫ Bohr – quantized, permitted orbits and quantum jumps for atoms