Chemical and nuclear reactions can be described in similar ways using mathematics. In fact, both of these types of reactions are commonly expressed by equations. There is, however, unique properties in the nature of each of these reactions. The main difference between these phenomena is in how the reaction occurs at the atomic level. Primarily, chemical reactions only involve the electrons of an atom while nuclear reactions will involve the nucleus of an atom.
Chemical reactions are the most common type of atomic interaction on Earth, and the one that most people remember learning about in their high school science classes. A chemical reaction only involves only the electrons of a group of atoms. During a chemical reaction, each atom will form or break apart a bond with another atom. These bonds are actually the sharing of electrons between atoms. When a bond forms, the electrons of each atom will enter the orbit of the other atom and essentially orbit the nuclei of both atoms. When a bond breaks, the electrons resume their “usual” orbit around their own nuclei.
In a chemical reaction, the nucleus of each atom involved does not change. As such, the same number and types of atoms are present after the reaction as there were before the reaction. For example, a bonding between sodium and chloride will result in the compound known as sodium chloride being formed. If five atoms each of sodium and chloride go into the reaction, then five molecules of sodium chloride will be created. No elements will transform into other elements during a chemical reaction.
On the other hand, a nuclear reaction will change of the composition of the nucleus of the atom or atoms involved in the reaction. This is typically done in two ways. The first process, fission, involves splitting one nucleus into smaller nuclei. The second method is fusion in which multiple nuclei are joined together to create a larger nucleus.
During a nuclear reaction, a portion of the matter in the original atom or atoms is converted into energy. This means that the resulting products of a nuclear reaction have less mass than all of the original material used in the reaction. This also means that after a nuclear reaction takes place there are a different number of atoms than what was originally present at the beginning of the reaction. The types of elements that are present are also different.
