Complete the following two statements regarding quantum-mechanical concepts associated with the Bohr model of the atom and refinements that resulted from the wave-mechanical atomic model. " Two important quantum-mechanical concepts associated with the Bohr model of the atom are that electrons are particles moving in Enter your answer for the missing word between words "moving in" and "orbitals" in accordance to the question statement discrete orbitals, and electron energy is quantized into Enter your answer for the missing word after words "quantized in" in accordance to the question statement levels . (b) Two important refinements resulting from the wave-mechanical atomic model are that the electron position is described in terms of a Enter your answer for the missing words after words "in terms of a" in accordance to the question statement electron cloud , and electron energy is quantized into both shells and subshells--each electron is characterized by Enter your answer for the missing word after words "is characterized by" in accordance to the question statement quantum numbers."