COMPOUNDS AND THEIR PROPORTIONS
All elements are represented by a chemical symbol. It is either a single capital letter, or a capital letter followed by a small letter.
Examples: Ca = calcium Cu = copper
C = carbon N = nitrogen
Combinations of symbols represent compounds. These compounds are called chemical formulas.
Example: H20 2 hydrogen atoms
1 oxygen atom
If no number is shown beside the symbol, a 1 is understood.
If more than 1 atom is present, a small number is shown after the atom to indicate how many atoms are in the compound.
NaHCO3 = Sodium Hydrogen Carbonate (baking soda) 1 atom Na = Sodium
1 atom H = Hydrogen
1 atom C = Carbon
3 atoms O = Oxygen