A molecule is two or more atoms bonded together chemically. An atom is the most basic unit of matter. When atoms are chemically bonded together with covalent bonds, molecules are formed. Molecules can be very small like water molecules or extremely large like proteins such as hemoglobin. Upon examination of a chemical formula for a molecule we see the element symbols marked with a subscripted number. The number represents the amount of that atom present within the molecule. If we are looking at water which has a chemical formula of H2O, this refers to 2 atoms of hydrogen bonded to one atom of oxygen.
1. Carbon dioxide - CO2
2. Water - H2O
3. Oxygen we breathe into our lungs - O2
4. Sugar - C12H22O11
5. Glucose - C6H12O6
6. Nitrous oxide - "Laughing gas" - N2O
7. Acetic acid - part of vinegar - CH3COOH