Chemical Timeline

Plum Pudding Model

460

This is the plum Plum Pudding Model.

Concept of the Atom

460

Democritus discovered concept the atom and introduced it in 460 B.C.
In order to explain the change around us from basic, unchangeable substance he created a theory that argued that there are various basic elements which always existed but can be rearranged into many different forms.
Fact: Democritus was a great philosopher in his time. He is the one who proposed the Ancient Greek Model which states that "atoms" are the smallest piece of an object

Peloponnesian War

464

An earthquake in ancient Sparta, Greece leads to a Helot uprising and strained relations with Athens, one of the factors that lead to the Peloponnesian War. Picture: This picture represents the Peloponnesian War.

Lewis and Clark

Jan 18, 1804

Lewis & Clark begin their great exploration. Picture: This picture is of Lewis and Clark on their exploration.

Electron Discovery

Jan 1, 1897

J.J. Thompson discovered that atoms have electrons (negative charge) in 1897.
Thomson was experimenting with currents of electricity inside empty glass tubes. He was investigating a long-standing puzzle known as "cathode rays." The rays are made up of electrons.
Facts: he quoted "The most hazardous part of our expedition to Africa was crossing Piccadilly Circus."

Thompsons Bun model

Jan 2, 1897

Thompson proposed a current bun model.

Nucleus

Jan 1, 1911

In 1911 Ernest Rutherford finds that an atom has a small, dense, positively charged nucleus.
He used the Gold Foil experiment.
Fact: Rutherford studied at Canterbury College, University of New Zealand before moving to England in 1895 for post graduate study at Cavendish Laboratory, University of Cambridge.

Gold Foil Experiment

Jan 2, 1911

This is the Gold Foil Expeirement Rutherford used to discover atoms have a positive charge called protons and neutral charged called neutrons.

Bombing Experiments

Jan 7, 1911

1st airplane bombing experiments with explosives. Picture: Represents our first bombing experiments

Atoms Have Different Energy Levels

Sep 18, 1913

Neils Bohr discovered that atoms are at different energy levels.
He used the Bohr Model to show this.
Fact:Niels Henrik David Bohr, who won the Nobel Prize for Physics in 1922, allegedly taught himself English by reading Dickens' Pickwick Papers over and over again.

Bohr Model

Sep 19, 1913

Bohr used this model to show atoms have different energy levels.

Protons

Jan 1, 1920

In 1920 Ernest Rutherford discovered that there are Protons and Neutrons in an atom.
He used the gold foil experiment and Kinematics.
Facts: •Rutherford studied at Canterbury College, University of New Zealand before moving to England in 1895 for post graduate study at Cavendish Laboratory, University of Cambridge.

Neutrons

Jan 1, 1932

In 1932 James Chadwick confirms that there are neutrons in the nucleus.
He bombarded the alpha rays (coming out from a natural radioactive material) onBeryllium atom and observed that Beryllium artificially became radioactive for a short time it emitted material rays containing neutral particles having mass almost equal to proton he proposed the name Neutron for the newly discovered particle,
Fact: He went to Victoria University

Neutron Discovery

Sep 18, 1932

Chadwick discovered the neutron by smashing alpha particles into beryllium, sending the released radiation to paraffin wax containing hydrogen atoms.

Electrons move in orbitals

Sep 18, 1932

they were arranged in orbitals which were systematically distributed within Electron Clouds.
He defined an orbital as: The region of space that surrounds a nucleus in which two electrons may randomly move.
He used the Quantium Model.
Facts:In 1933 he shared the Nobel Prize for Physics with the British physicist P.A.M. Dirac.

Quantium Model

Sep 19, 1932

Erwin Schrodinger used this model to show electrons move in orbitals.

WWII

Sep 17, 1939

WWII was a big historcal event during this time. Picture: The picture represents WWII

Hydrogen Bomb

Sep 17, 1950

U.S. President Truman Orders Construction of Hydrogen Bomb Picture: shows the hydrogen bomb.

Terrorist Attack at Olympics

Sep 17, 1970

Terrorist attack at the Olympic games in Munich Picture: olympics symbol

Hubble Telescope

Sep 17, 1990

Hubble telescope was launched into space Picture: This is the hubble telescope