Florida Statewide Science Assessment (SSA) Practice Exam

When two or more elements come together and form new substances through chemical bonds, the result is a compound. A compound is defined by that joining of elements in a fixed ratio, creating properties that are different from the individual elements. Elements are pure substances made of one kind of atom, while mixtures are combinations of substances that aren’t bonded and can be separated by physical means. So a substance made of two or more elements joined by chemical bonds is a compound, such as water (H2O) or carbon dioxide (CO2).