1. Compute the orbital radius, velocity and energy of the first three levels of Hydrogen and Uranium. What general conclusions can you draw?
2. Compute the wavelengths for Hydrogen atom transitions between all levels up to 7. Do not round until the end of your computations, since you may have very small numbers in denominators during the calculation.
3. 0.2 % of the solar radiation which reaches the surface of the earth
lies in the 290 to 313 nm range, which causes sunburn. If the total
radiation hitting the Earth's surface is 2100 J / cm 2 per 12 hours, and the burning efficiency is 50%, approximately how many photons caused the sunburn you received over 1 m 2 of your body by staying out in the sun for four hours?
4. When completely adapted to darkness, the human eye is able to detect a point light source if the power delivered to the retina is larger than 2 x 10 - 16 W. For a wavelength of 550 nm, how many photons must strike the retina each second to be detected?
