make up all the diverse types of matter in the universe.
The process by which two different elements come together to form a compound is one
example of achemical reaction. For example, hydrogen and oxygen together form water.
Water has the properties of a liquid, not the properties of the gases hydrogen and oxygen.
Water is theproduct, or end result, of the chemical reaction while hydrogen and oxygen
are thereactants, or “ingredients” necessary for the chemical reaction.
One important chemical reaction in your everyday life is oxidation, or the combination of
oxygen and another element. Examples of oxidation are burning and rusting. When oxygen
combines with gas on your stove top, the reaction releases heat that you can use to cook
with. (In fact, since fires need oxygen to burn, most fire extinguishers are composed of
heavier gasses that will displace the oxygen, smothering the fire.) Rust is formed when
oxygen combines with iron (Figure2.9). These are a few examples of chemical reactions.
Figure 2.9: Rust is the result of a chemical reaction between iron and oxygen. ( 16 )Organic Compounds
The chemical components of living things are known asorganic compounds, which means
they contain the element carbon (C). Living things are made up of compounds that are quite
large. These large compounds molecules, known asmacromolecules, are made of smaller
molecules. You might recognize some of these organic molecules as parts of the food you eat
(Figure2.16). Through eating food, we obtain the organic molecules we need to grow and
be healthy.