The linkage between two atoms or radicals of a chemical compound.

The force that holds two or more units of matter together.

A certificate sold by a corporation or government entity to raise funds. It is basically a form of “IOU” upon which the corporation or government entity will pay interest to the bondholder for a given period of time, and pay the bondholder the amount borrowed (the principal amount) at the end of that time. Some bonds qualify as “tax-exempt,” meaning that the bondholder does not have to pay taxes on the interest earned.

A force that binds ions or atoms together. It is represented by a line drawn from one molecule or atom to another as in H — O — H.