Chemists use a wide array of techniques for determining the exact composition and structure of a compound. One of the most robust and interesting of these is nuclear magnetic resonance (NMR) spectroscopy. In this problem, you will see how NMR spectroscopy allows for the precise determination of the structure of an organic compound. Nuclei with odd numbers of neutrons or protons have a magnetic moment. In the presence of a strong magnetic field, some nuclei will align parallel and some will align antiparallel to the field. If a sample is subjected to electromagnetic radiation with photon energy equal to the difference in energy between the two nuclear alignment states, some nuclei in parallel states will absorb a photon and flip to antiparallel states. Suppose that a small shift Δf in the frequency of the absorbed radiation is observed. This shift is attributed to a small change Δμ in the magnetic moment. What is the value of Δμ ?
Express your answer in terms of Δf , B , and h .

Which is not a step in the rock cycle?

The desk has a weight of 75 lb and a center of gravity at g. determine the initial acceleration of a desk when the man applies enough force f to overcome the static friction at a and b. also, find the vertical reactions on each of the two legs at a and at b. the coefficients of static and kinetic friction at a and b are ms = 0.5 and mk = 0.2, respectively

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.