nuclear magnetic resonance science definition

The absorption of electromagnetic energy (typically radio waves) by the nuclei of atoms placed in a strong magnetic field. The nuclei of different atoms absorb unique frequencies of radiation depending on their environment, thus by observing which frequencies are absorbed by a sample placed in a strong magnetic field (and later emitted again, when the magnetic field is removed), it is possible to learn much about the sample's makeup and structure. Nuclear magnetic resonance has no known side effects on the human body, and is therefore used to analyze soft body tissues in magnetic resonance imaging (MRI).