<Ul> <Li> Electron spin resonance </Li> </Ul> <Li> Electron spin resonance </Li> <Dl> <Dd> A widely used technique for studying free radicals, and other paramagnetic species, is electron spin resonance spectroscopy (ESR). This is alternately referred to as "electron paramagnetic resonance" (EPR) spectroscopy . It is conceptually related to nuclear magnetic resonance, though electrons resonate with higher - frequency fields at a given fixed magnetic field than do most nuclei . </Dd> </Dl> <Dd> A widely used technique for studying free radicals, and other paramagnetic species, is electron spin resonance spectroscopy (ESR). This is alternately referred to as "electron paramagnetic resonance" (EPR) spectroscopy . It is conceptually related to nuclear magnetic resonance, though electrons resonate with higher - frequency fields at a given fixed magnetic field than do most nuclei . </Dd>

What must be the same about two radicals before they can be added