The definition of “atomic theory is a theory of the nature of matter: all materials, substances are composed of tiny particles or atoms of “a relatively small number of types and all atoms of the same species are uniform in size, weight and other properties” (Merriam-Webster). When you hear the words “Atomic Theory,” you associate words and people like the atom with the Greek philosopher Democritus, motion with Isaac Newton, the periodic table with Dmitri Mendeleev, the “Manhattan Project” with Albert Einstein (Buescher, 1996). but does John Dalton appear when he speaks of the “atomic theory”? Unlikely, unless you took a college-level science or chemistry class. John Dalton is a man who has had a great impact in the field of chemistry. “Atomic Theory”, our modern technology and science would not be the same. Without John Dalton, we will never know if GJ Stoney was able to discover "the electron", if Wilhm Roentgen discovered "X-rays", or if Marie Slodwka Curie discovered "radioactivity", Albert Einstein discovered the "E =MC^2”. ", or the completion of the "Periodic Table" by Dmitri Mendeleev (Buescher,