-
Oxygen (1770)
Joseph Pristley discovered oxygen. Antoine Levosier clarified the nature of elements. Pristley also invented carbonated water by dissolving fixed air in water. He called this new gas dephlogisticated air. Lavosier names oxygen and works to create a chemical nonmenclature which is the base of the system. -
Electricity Transforms Chemicals (1807-10)
Humphrey Davy finds that electricity forms chemicals. He uses an electric pile(battery) to seperate salts by a process known as electrolysis. -
Atomic Theory (1808)
John Dalton provided a way of linking invisible atoms to measurable quantities like the volume of a gas or mass of a mineral. His atomic theory states that the elements consist of tiny particles called atoms. -
Atoms Combine into Molecules (1811)
Amedeo Avogadro finds that the atoms in elements combine to form molecules. He said the equal volume of gases under equal conditions of temperature and temperature contain equal number of molecules. -
Synthesis of Urea (1828)
Friedrich Woehler synthesized urea from inorganic materials and proved that materials made of living things can be reproduced by nonliving substances. Until 1828 it was believed that organic substances could only form with the help of vital force. -
Chemical Structure (1850)
Friedrich Kekule figured out the chemical structure of benzene. He came up with the ring shape of the benzene molecule after dreaming of a snake seizing its own tail. -
Atoms Have Signature Lights (1850)
Gustav Kirchhoff and Robert Busen find that each element absorbs or emits light at specific wave lengths, producing specific spectra. -
Periodic Table of Elements (1860-70)
Dmitri Mendeleev realized that if all of the sixty three known elements are arranged in order of increasing atomic weight, their properties are repeating because of a certain periodic cycle. -
The Electron (1897)
JJ Thompson discovers that the negatively charged particles emitted by cathode ray tubes are smaller than atoms and part of all atoms. They are called "corpuscles". -
Electrons for Chemical Bond (1913)
Niels Bohr published his model of atomic structure in which electrons travel in specific orbits around the nucleus and the chemical properties of an element are determined by the number of electrons in its atoms outer orbits.