Spectroscopy studies the interactions between matter and electromagnetic radiation and is an important tool in many fields. Some common spectroscopic techniques are infrared spectroscopy, which is used to identify purified molecules; nuclear magnetic resonance spectrophotometry, which detects magnetic movement in atomic nuclei and contributes to research on organic molecules; and ultra-violet and visible light spectrophotometry, which measures transitions of bonding and non-bonding outer electrons and is used in biochemical analyses.