Protons are the positively charged particles found in the nucleus of an atom. In terms of their magnetic properties, protons can be classified into two categories: equivalent and non-equivalent protons.
Equivalent protons are protons that have the same chemical environment in a molecule. This means that they experience the same local electronic and magnetic environment, and as a result, they produce the same NMR signal. For example, in a molecule of ethyl alcohol (CH3CH2OH), the two methyl (CH3) groups are equivalent because they are attached to the same carbon and are surrounded by the same atoms.
Non-equivalent protons, on the other hand, are protons that have different chemical environments in a molecule. This means that they experience different local electronic and magnetic environments, and as a result, they produce different NMR signals. For example, in a molecule of acetone (CH3COCH3), the three methyl (CH3) groups are non-equivalent because they are attached to different carbons and are surrounded by different atoms.
The distinction between equivalent and non-equivalent protons is important in NMR spectroscopy, as it allows chemists to distinguish between different types of protons in a molecule and determine their relative abundance and position in the molecule.