Coulomb's law is absolutely fundamental, of course, to any student of electrical phenomena in physics. However, it is just as important in understanding and interpreting many kinds of chemical phenomena. For example, an atom is, in one respect, nothing other than a collection of electrical charges, positively charged protons, and negatively charged electrons. Coulombic forces exist among these particles. For example, a fundamental problem involved in a study of the atomic nucleus is explaining how the enormous electrostatic force of repulsion among protons is overcome in such a way as to produce a stable body.
Coulombic forces must be invoked also in explaining molecular and crystalline architecture. The four bonds formed by a carbon atom, for example, have a particular geometric arrangement because of the mutual force of repulsion among the four electron pairs that make up those bonds. In crystalline structures, one arrangement of ions is preferred over another because of the forces of repulsion and attraction among like-charged and oppositely-charged particles respectively.