Chemical reactions are the heart of chemistry. People have always known that they exist. The Ancient Greeks were the firsts to speculate on the composition of matter. They thought that it was possible that individual particles made up matter. Later, in the Seventeenth Century, a German chemist named Georg Ernst Stahl was the first to postulate on chemical reaction, specifically, combustion. He said that a substance called phlogiston escaped into the air from all substances during combustion. He explained that a burning candle would go out if a candle snuffer was put over it because the air inside the snuffer...
one molecule at a time. The molecules are stimulated in a pattern giving the wanted results. This discovery opens doors for nanoengineering and material sciences. It gives a good view of what happens, one molecule at a time.

Chemical reactions are a large part of chemistry. This paper is an overveiw of that extensive subject. It gives a good idea about the history of chemical reactions as well as the future. Hopefully, there will be no end to the expansion of chemistry and our knowledge. Since Scientists are still experimenting, chemical reactions will always be a part of chemistry.