8. Carbon-carbon single bonds in organic and biological molecules have energies around 83 kcal . From the answers to Problems 5-7, would you expect that red-orange light is capable of breaking carbon-carbon bonds and disrupting molecules?

9. What is the energy per mole of photons of ultraviolet light of wavelength 2400 ? (See Problem 8.) Should this radiation be capable of disrupting organic molecules? Why are UV lamps used as germicidal sterilizers?

10. When light of frequency falls on a photocell, an individual electron in the metal surface is given an energy kick of E = h. The kinetic energy that the ejected electrons will have is given by KE = h - , in which is called the "work function" of the metal, and is the energy needed to pull an electron out of the metal surface. The work function is similar to the first ionization energy, but applies to the removal of an electron from a block of metal instead of from an isolated gaseous atom. The incoming photons of light must have energy at least as large as , or they cannot remove electrons at all. Does this mean that there is a maximum wavelength, or a minimum wavelenlgth, for photoemission of electrons from a metal surface?