Atom Model Evolution

This is the evolution of the Atom Model from Dalton to Bohr

Dalton's Model

John Dalton (1766-1844) was an English chemist and physicist who made many contributions to chemistry. This model was based on his experiments he did in combining elements.

The Dalton Model consisted of a sphere, which varied in size, colour, mass, etc. Different elements had different properties.

Thomson's Model

Joseph John Thomson (1856-1940) was an English physicist who discovered the electron. In the 1890s, Thomson was experimenting with beams of particles produced in a vacuum tube.

The Thomson Model consisted of the same sphere Dalton theorised to be the atom, except it had no different properties when compared to other elements, except the number of electrons wedged inside of it.

Rutherford's Model

Ernest Rutherford (1871-1937) began working with radioactive substances in England with J.J. Thomson. Rutherford later did research at the McGill University in Montreal, where he performed an experiment which led to the discovery of the nucleus.

The Rutherford Model consists of the positively-charged nucleus in the center and negatively charged electrons orbiting around the nucleus.

Bohr's Model

Neils Bohr (1885-1962) was a Danish physicist who worked under Rutherford in England. He proposed that electrons surrounded the nucleus in specific energy levels. He found evidence for this by examining the light released by hydrogen atoms when they are made to glow in a tube.

This second-to-last model consists of the nucleus in the center with electrons orbiting the nucleus. Sort of like the Rutherford Model, but on seperate "rings" which represent energy levels.

The End!

That about concludes our journey through the history of the atom. Thank you for visiting my site!