The Next Atomic Model Timeline Project

Democritus

442 BCE

Democritus' discovered that matter consisted of invisible particles and that they were unchangeable and indestructible. His atomic model was solid and all atoms differed in size and shape.

Daniel Bernoulli

1738

Daniel Bernoulli proved Democritus correct by providing proof that tiny atoms existed. He proved that the behaviour of matter depended on what atoms it was made from.

Joseph Proust

1794

Joseph Proust contributed to the Atomic Model by discovering the Law of Constant Composition. This helped scientists understand that compounds are composed of exact elements no matter how the compound is created.

John Dalton

1803

In John Dalton's Atomic Model each element has its own atom. Atoms can combine to make a compound. For example, water is made when 2 hydrogen and 1 oxygen are combined.

Michael Faraday

1812

Michael Faraday's discovery led to the idea that atoms have an electrical component. He discovered that atoms could be placed under much strain before the bonds that held them together were broken.

Marie and Pierre Curie

1902

Marie and Pierre Curie researched radioactivity in atoms. They discovered that radioactivity does not depend on how atoms are arranged but comes from within atoms.

J.J. Thomson

1904

J.J Thomson's Atomic Model, also known as The Plum Pudding Model, changed the modern view of the atom because there were parts inside the atom that were negatively and positively charged electrons. In this model, positive fluid (plum pudding) kept the negatively charged electrons in the atom.

Albert Einstein

1905

Albert Einstein proved mathematically the existence of atoms using statistics and probability. He created a mathematical method to calculate the size of atoms.

Ernest Rutherford

1911

Lord Ernest Rutherford discovered the nucleus of the Atomic Model, which is the small centre of the atom that is filled with positive charges. In his model, negatively charged electrons surround the nucleus and are held here by electrical forces.

Niels Bohr

1913

Niels Bohr's Atomic model explained that electrons moved in fixed, circular orbits around the nucleus (electron shells). These shells are at set distances form the nucleus and the electrons can jump from one shell to another by absorbing energy.

Ernest Schrodinger

1926

Ernest Schrodinger's Atomic Model discovered that electrons don't move in orbits, but move in waves (clouds) with no exact location. This Atomic Model is known as the Quantum Mechanical Model and predicts where the electrons are, based on where the "cloud" is most dense.

James Chadwick

1932

James Chadwick's Atomic model discovered neutrons. The neutron was difficult to locate because it did not repel the protons. Chadwick was able to separate the neutron and discovered it was neutral and had no charge.