9452222 Horner North Central College proposes to incorporate several laser experiments into its physical chemistry laboratory. An introductory physics laboratory will also be affected. Short timescale (50 ns - 10 ms) events heretofore inaccessible in the laboratories will be investigated using chopped or pulsed lasers. In the physical chemistry laboratory a chopped helium-neon laser beam will be used to study the thermal lens effect and measure the heat capacity of a solvent. A pulsed nitrogen laser will function as the excitation source in two other physical chemistry experiments. In one, the kinetics of a colorful photoisomerization reaction will be studied using the pulse-probe method. In another experiment students will measure luminescence lifetimes to learn about factors influencing radiationless electronic relaxation of excited metal ions, with special emphasis upon collision-induced energy transfer. Chemistry and physics students in an introductory physics laboratory will receive an early exposure to modern optical methods as they use the pulsed nitrogen laser to determine the speed of light. Several benefits will accrue from this project. Topics previously encountered only in the lecture portion of physical chemistry will be brought to life in the laboratory. The instrumental backgrounds of North Central College chemistry students will be greatly enhanced by their encounters with the modular (rather than "black- box") experimental apparatus, and students will get a taste of modern experimental research methods in physical chemistry.
