The Basics of Chemical Formulas

Every piece of matter is composed of some types of atoms and these atoms could be combined into molecules and the molecules could be combined in many different ways. Each element is represented by one or two letters. If there are two letters then the first would be a capital letter and if there is a second letter for the same element then it would be written in lower case. The chemical symbol for Hydrogen is "H", while the chemical symbol for Helium is "He". Hydrogen bonds with Oxygen to form water the result would be a water molecule with the formula H2O. The 2 would normally be written slightly lower and smaller that represented here and would mean that 2 atoms of Hydrogen are bonded to one atom of Oxygen to form a water molecule. The hydrogen atoms join to the oxygen at an angle and this angle helps to explain how water forms a crystal structure as it freezes. The angle between the two hydrogen atoms is about 104.4 degrees.

The formula for table salt is NaCl meaning that one atom of Sodium is bonded to one atom of Chlorine to form table salt. This is then one molecule of table salt, but is not a fully accurate description of the salt we use at the kitchen table because the salt we actually use at the kitchen table does have impurities and sometimes has the addition of iodine which can be added to help prevent thyroid diseases.

A formula written like the table salt formula and the water formula above does not tell us much about the structure of the atoms in the molecule. For example we know the distance from the oxygen atom to the hydrogen atom is about 95.8 picometers (about 1 X 10-12 m.) which is a very small distance, but still could be calculated. The structure is perhaps even more important in determining the properties than the numbers of atoms.

The formula for sugar is C12H22O11 (numbers should be subscript) shows that sugar is a relatively simple molecule, but it also helps to explain some of it's ability to provide energy through the process of metabolism. Your body must break the sugar down to make use of the potential energy stored in the molecule.