Electronic transitions (i. e., absorption of uv or visible light) of the conjugated molecule butadiene can be approximated using the particle-on-a-line model, assuming one of the pi electrons can move along the whole four-carbon chain. a molecule of butadiene is found to absorb light of 215 nm corresponding to the electron being excited from the n=2 to n=3 levels. use this to determine the length, in angstroms, of the four-carbon chain to which the electron is confined.

Steam is generated in a boiler of a cogeneration plant at 10 mpa and 450°c at a steady rate of 5 kg/s. in normal operation, steam expands in a turbine to a pressure of 0.5 mpa and is then routed to the process heater, where it supplies the process heat. steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. in this mode, no steam passes through a condenser, which operates at 20 kpa. (a) determine the power produced in the turbine and the rate at which process heat is supplied in this mode. (b) determine the power produced in the turbine and the rate of process heat supplied if only 60 percent of the steam is routed to the process heater and the remainder is expanded to the condenser pressure. (3.32 mw; 9.69 mw; 4.25 mw; 5.82 mw)

Which types of electromagnetic waves have higher frequencies than the waves that make up ultraviolet light? check all that apply. radio waves infrared light microwaves gamma rays visible light x-rays

Which terms describe the purpose of antennas on devices that use radio waves? transmit and receivemodify and amplifyamplify and receivemodify and transmit