J.J. Thomson was a scientist who was born in a small suburb, Cheetham Hill, in side of Manchester, England. He was born in the year 1856 but later on was a big part in science, he ended up contributing to more than just the atomic theory. Thomson discovered that atoms can be cut. He found this out while studying rays traveling between charged metal plates in a vacuum tube. He discovered that the rays were consisted of negatively charged particles. He had just discovered electrons. He discovered all of this on a trip from America. Since electrons are so small, he believed that they could only be from inside of the atom. Since Thomson's discovery of the electron, John Dalton's theory that atoms are indivisible had to be changed.