Dear Chemists,

Lately, we’ve been talking about chemical reactions. We’ve learned that chemical reactions form new substances. Today we’ll talk about what must always stay the same in any chemical reaction: the amount of matter. This is the law of the conservation of mass. Scientific laws are different than societal laws because they can never be broken.

Scientists have long known about this law. The ancient Greeks knew that “nothing comes from nothing,” but it took many centuries before scientists were able to use the law of conservation of mass to create the field of chemistry. Through experiments, close investigations, and communication of their results with others, scientists in the 1600 and 1700s uncovered entirely new insights about the transformation of substances after chemical reactions.

Isn’t it comforting to know that despite all the changes and transformations going on, there’s at least one thing that stays the same? It sure makes the world a whole lot easier to study and understand.

Sincerely,

Mr. H