81. There is 1 carbon, 2 chlorine and fluorine atoms in Freon 12. To draw them it forms a cross with C in the middle and Cl and F both on the opposite side.
Water is an incomplete combustion as water is still produced by carbon monoxide and carbon are produced instead of carbon dioxide.
Oxidation occurs when an atom, molecule, or ion loses one or more electrons in a chemical reaction. When oxidation occurs, the oxidation state of the chemical species increases. Oxidation doesn't necessarily involve oxygen!
