Two basic laws of chemistry are the law of conservation of mass and the law of constant composition. Which of these laws do the following illustrate?
1. Lavoisier found that when mercury (II) oxide, Hgo, decomposes the total mass of mercury (Hg) and oxygen formed equals the mass of mercury (II) oxide decomposed.
2. Analysis of the calcium carbonate found in marble mined in Carrere, Italy, and in the stalactites of the Carlsbad Caverns in New Mexico gives the same value for the percentage of calcium in calcium carbonate.
3. Hydrogen occurs as a mixture of two isotopes, one of which is twice as heavy as the other.