section_path: Proton in chemistry/Proton nuclear magnetic resonance (NMR)
section_name: Proton nuclear magnetic resonance (NMR)
paragraph_text: Proton nuclear magnetic resonance (NMR)
  
  Also in chemistry, the term proton NMR refers to the observation of hydrogen-1 nuclei in (mostly organic) molecules by nuclear magnetic resonance. This method uses the quantized spin magnetic moment of the proton, which is due to its angular momentum (or spin), which in turn has a magnitude of one-half the reduced Planck constant. (ℏ / 2 {\displaystyle \hbar /2}). The name refers to examination of protons as they occur in protium (hydrogen-1 atoms) in compounds, and does not imply that free protons exist in the compound being studied.