An Atom is the smallest unit into which matter can be divided without the release of electrically charged particles. It also is the smallest unit of matter that has the characteristic properties of a chemical element. As such, the atom is the basic building block of chemistry. John Dalton - John Dalton developed the first useful atomic theory of matter around 1803. Whilst studying meteorology, Dalton concluded that evaporated water exists in air as an independent …showed first 75 words of 1042 total…

…showed last 75 words of 1042 total…the centre of the atom was a super dense nucleus and totally destroys the Thomson model. Rutherford's model of the atom wasn't as widely accepted as Thomson's model because there were still few people who support the Thomson model no matter what. Even though some of the details of Dalton's, Thomson's and Rutherford's original atomic theories are now known to be incorrect, the core concepts of the theories are the foundations of modern physical science.