The law of the conservation of mass states that, in a system, mass or matter can neither be created nor destroyed. It can however undergo either a physical or chemical change. When a change in the state of a matter occurs, the physical properties of the matter will change. Its mass however, remains constant. If 100g of ice were melted, you would have 100g of water. This could be boiled to make 100g of steam, although this is difficult to measure. If all the steam could be collected and condensed, it would again form 100g of water. Freezing would again produce 100g of ice. Similarly, a candle with a mass of 100g, which is burning, may appear to burn away to nothing, but it actually produces 100g of products. This is called the conservation of mass. When chemical changes occur, new substances are often formed which makes it difficult to reverse them. The total amount of material will remain the same. Even though matter may have changed appearance, it cannot be destroyed nor created simply changed into something else.
