Sam does an experiment in his lab. He discovers that the mass of the reactants before his experiment is the same as the mass of the products after his experiment. What did he prove?
The law of conservation of mass
The law of conservation of energy
O Physical properties only change during chemical reactions.
He messed up the experiment because the mass should have been different

Peat deposits are found in waterlogged places where dead plant material piles up. when peat is buried, it undergoes compaction. it is subjected to heat and pressure for a long time, and a lot of water is squeezed out during this process. nearly ten vertical feet of original peat material becomes one vertical foot of coal. which of these remains unchanged in the system during the conversion of peat to coal? a) area b) density c) mass d) volume