heisenberg's uncertainty principle of quantum mechanics (a) is a mathematical formula that lets us calculate the momentum of an electron or other particle if we know its position. (b) relates the energy and frequency of an electron or other particle. (c) is a mathematical formula that lets us calculate the velocity of an electron or other particle if we know its energy. (d) expresses a relationship between the wavelength and frequency of a photon or other particle. (e) does none of the above.