Nuclear magnetic resonance (NMR) spectroscopy. Part I

At the end of this activity, students should be able to:
– explain how atomic nuclei behave in an external magnetic field, depending upon whether they posses nuclear spin or not
– explain why a magnetic field causes the energy levels of nuclei possessing nuclear spin to split
– explain the nuclear absorption of electromagnetic radiation by nuclei placed in a magnetic field
– describe the construction and operation of an NMR spectrometer and how an NMR spectrum is recorded
– explain the term 'chemical shift' and discuss why hydrogen atoms in organic molecules may produce more than one NMR absorption signal
– explain why TMS has been chosen as a standard in NMR spectroscopy
– identify equivalent and non–equivalent 1H atoms in the molecule
– predict the number of absorption signals in low–resolution proton NMR spectra, as well as their relative intensity.