Tetramethylsilane is used as an internal standard for calibration in this technique’s “proton” and “carbon-13” variants. For 10 points each:
[10m] Name this spectroscopic technique in which signals are normalized to chemical shift values. This technique investigates the structure of molecules by applying a strong magnetic field before perturbing them.
ANSWER: NMR spectroscopy [or nuclear magnetic resonance spectroscopy; accept proton NMR; accept carbon-13 NMR]
[10h] The sample holders in NMR spectrometers perform this action to average out diffusional motion. In one form of NMR, this action is performed at a “magic angle” of 54.7 degrees to improve resolution.
ANSWER: spinning [accept magic angle spinning or magic angle turning; accept word forms like spun or turned; accept synonyms like rotating or word forms like rotation]
[10e] Magic angle spinning is used in a variant of NMR that analyzes samples in this state of matter. Substances in this state of matter have closely packed atoms and have a definite shape and volume.
ANSWER: solid [accept solid-state NMR or solid-state nuclear magnetic resonance]
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