One such compound is water. A water molecule consists of 2 atoms of hydrogen bonded to one atom of oxygen. Another common compound is table salt.
Table salt is the compound sodium chloride.
Each molecule of salt is composed of one atom of sodium bonded to one atom of chlorine. This bond gives the molecule completely different chemical properties than its parent elements. We can mix it with food or water with little consequence. Yet sodium is a metal that is violently reactive with water. If sodium comes into contact with water, the hydrogen gas that is released will actually burst into flames.