Atomic Timeline

The Alchemists

500 BCE

Turned simple metals into silver and gold. They believed substances, mind, philosophies, religion, magic, and astrology were all related

Democritus

430 BCE

First to believe atoms were uniform. solid, hard, incompressible, and indestructible. He was also known as the "Laughing philosopher" since he was cheerful at work

Plato

427 BCE

he believed atoms broke down mathematically and set up the theory for Aristotle. He founded and taught at his school.

Robert Boyle

1660

Proposed that elements are made of corpuscles of different chemical substances. He also created the idea of elements

Antoine Lavoisier

1772

Created the atomic model, and found total mass equals reactants in chemical reactions. He was eventually elected to French Academy of Science

John Dalton

1803

First scientist to explain behavior of atoms in terms of weight. He started teaching when he was 12.

Billiard Ball Model

1803

Dalton came up with this model since he believed atoms were the smallest particle

Amedo Avogadro

1811

Discovered that equal volume and temperature equals the number of molecules, and that gasses are made of 2 atoms. He was the first to find the existence of molecules in the form of elements

Dimitri Mendeleev

1871

Russian chemist who properly set up the current periodic table. He graduated with a gold medal from the Main Pedagogical Institute in Saint Petersburg

Ernest Rutherford

1894

Physic from New Zealand who found radioactivity rose formation in gasses. And is known as father of nuclear physics.

JJ Thompson

1894

Physic who discovered electrons in atoms. He concluded all matter was made up of "tiny corpuscles" now known as electrons.

Solar sytem Model

1897

Also known as the Bohr-model, named after the creator, Neil Bohr. The solar system model consists of a small nucleus surrounded by electrons.

Pierre and Marie Curie

1898

French scientists who discovered radioactivity and its elements. They won the Nobel prize in 1903 and 1911.

Plum Pudding Model

1904

Proposed by J.J Thompson and tries to explain electrons, and atoms with no charge.

Albert Einstein

1905

Mathematically proved existence of atoms, and won the Nobel prize in 1921

Robert Millikan

1910

Determined the magnitude of the electrons charged. And won the Nobel prize in 1923

Neils Bohr

1911

Created the theory of placement of the electron, and won a Nobel prize the same time as Einstein

Henry G.J Mosley

1913

Showed the x-rays created by atoms, he created the chemical concept of the atomic number

Erwin Schrodinger

1926

Wrote the first mathematical equation to calculate energy levels of electrons in atoms. And was awarded the Nobel prize in 1933 for his discovery.

Electron cloud model

1926

Model of atom that includes nucleus and electrons, this was made by Erwin Schrodinger

Werner Heisenberg

1927

Formulated quantum mechanics in terms of matrices and terms. He discovered the "Uncertainty" principle. Which is particles position an momentum cannot be known exactly.

James Chadwick

1932

Discovered the Neutron Particle with no electrical charge. And won the Nobel prize in 1935