Ernest+Rutherford

__Ernest Rutherford__ In his atomic theory he describes an atom having a central positive nucleus and surronding negative electrons. He suggested most of the mass of an atom is in the small nucleus and the rest of the atoms take up empty space.

[[image:http://www.rsc.org/chemsoc/timeline//graphic/1911_gfoil_02.jpg width="612" height="396"]]

He discovered that radioactivity is the product of subatomic change and due to that Rutherford ended the chapter on Aristotles idea of physics which said that all matter is unchangeable.