1) A red laser pointer emits light with a wavelength of 640 nm . What is the frequency of this light? answer is in s^-1 2) What is the energy of one of these photons? answer is in J 3) The laser pointer emits light because electrons in the material are excited (by a battery) from their ground state to an upper excited state. When the electrons return to the ground state, they lose the excess energy in the form of 640 nm photons. What is the energy gap between the ground state and excited state in the laser material? answer is in J i was absent in class and my test is thursday anyone able to help?