Chemical shift

Chemical shift is a term used in nuclear magnetic resonance (NMR) spectroscopy to describe the variation in resonance frequency of nuclei in a magnetic field due to their electronic environment. When atomic nuclei are placed in a magnetic field, they resonate at specific frequencies. However, the presence of surrounding electrons influences these frequencies, leading to shifts in the resonance peaks observed in an NMR spectrum. ### Key Points about Chemical Shift: 1. **Units**: Chemical shift is measured in parts per million (ppm).