Development of the Model of the Atom-Individuals

460-370BC

Came up with the idea of the atom. Stated that all of matter is made up of atoms

Provided the method of gathering scientific facts

1803 AD

Formed the atomic theory which states that all matter is composed of tiny indestructible particles called atoms.

1898 AD

Discovered the electron and developed the plum pudding model

1909 AD

Used the results of his gold foil experiment to state that all the mass of an atom were in a small positively-charged ball at the centre of the atom.

1913 AD

Suggested that the electrons moved around the nucleus in successively large orbits. He also presented the Bohrs atomic model.

1817

A German scientist who put forward his law of triads. Each of his triads was a group of three elements. The appearance and reactions of the elements in a triad were similair to each other.

1864

Put forward his law of octaves. He arranged all the elements known at the time into a table in order of relative atomic mass. When he did this, he found that each element was similair to the element eight places futher on.

1869

A russian chemist who published a new periodic table. He rearranged the elements into groups of similair properties. This method of arranging elements meant that there were gaps in his table. He thought this meant that there were elements that hadn't been discovered. He also predicted the properties of several of the undiscovered elements.