Developing the Atmoic Theory timeline

410

Aristotle

Aristotle believed that all matter was up of four elements: fire, air, earth and water.
410

Democritus

If matter were to be divided into smaller and smaller pieces, it would eventually lead to the smallest piece possible in which Democritus reffed to as the atomos.
Period: 410 to Jan 1, 1900

Developing the Atomic Theory

Contribution of particular scientists to the atomic theory.
Oct 20, 1600

Robert Boyle

Helped develop a definition for the atmoic theory and helped with the 'death' of the four elements: fire, air, water, earth.
Oct 20, 1600

Isaac Newton

Atoms were pulled together by strong forces and attractions.
Oct 20, 1700

Joseph Priestly

Discovery of the gas named oxygen.
Oct 20, 1700

Antoine Lavoisier

Created the principle the law of conservation of mass.
Oct 20, 1800

John Dalton

Proposed a number of basic ideas revolving the atom as well as devising several element symbols.
Oct 20, 1800

Dmitri Mendeleev

Created the perodic table.
Oct 20, 1800

Henry Moseley

Number of protons in an element determines its atomic number.
Oct 20, 1900

Ernest Rutherford

Discovered the atomic nucleus.
Oct 20, 1900

James Chadwick

Inside the nuclues contains neutral particles called neutrons as well as positvely charged particles called electrons.
Oct 20, 1900

Niels Bohr

Proposed a model of an atom which stated that the outer shell could hold more electrons than the inner shell.

Aristotle