The Start Of The Atom Democritus was a young philosopher when he discovered "atomos," or invisible particles that make up matter. No one believed Democritus about his amazing discovery until he found evidence, a sandy beach that had a lots of sand with little pieces of rocks. Democritus then realized that he found the evidence he was looking for the sand was made up of tiny little particles that he could not see.
John Dalton said;"all matter is made of tiny indivisible particles called atoms" he also discovered when a chemical reaction happens no new atoms are created or could be destroyed for any reason.