Electrical effects play a major role in binding together the atoms and molecules that matter is made of. A molecule of water, for example, is made up of one oxygen atom, and two hydrogen atoms. Because the oxygen atom in effect hijacks the electrons from the hydrogen atoms, you could say that it has a negative charge, while the hydrogen atoms have a positive charge. The negative oxygen is attracted to the positive hydrogen atoms of other water molecules around it, and this electrical coupling, while not that strong, in effect creates water. It is one of the reasons that water in a normal state does not disintegrate.

The force generated between two bodies as a result of their charges is known as the Coulomb force, and the relationship between them as a Coulomb interaction. The Coulomb force is proportional to the product of the electrical charge of both bodies, and decreases exponentially as distance between the two bodies increases (i.e., it is inversely proportional to the square of distance). This is Coulomb's Law, named after Charles Augustin de Coulomb, the French physicist who discovered it in 1785.

Magnetic force is similar, with unlike poles attracting each other, and like poles repelling each other.

What is important here is that saying a force decreases exponentially as distance increases is the same as saying force increases exponentially as distance decreases. As such, Coulomb forces that are insignificant at distances existing in our everyday world take on enormous significance at the nano level, where distances are much smaller, and make their presence felt as attraction and repulsion between matter.

There are cases at the nano level where the particles being handled are individual electrons, and since electrons carry a negative charge and repel each other, they need to be contained in some way to prevent them from scattering. Having to think about such things is what makes the nano world so interesting.