-
Democritus
Democritus's life lasted from 460-370 BC. He was born in Abdera, Thrace. He postulated that matter had seedlike particles called atoms which means indivisible. He made this discovery in 440 BC. -
Aristotle
Aristotle (384-322 BC), Stagira, Greece. Believed for about 2000 years after he stated his theory, Aristotle's theory stated that all substances were built from 4 elements, earth, air, water, and fire. -
Antoine Lavoisier
He lived from 1743-1794. Was born in Paris, France. He made his discovery in 1778. He made the atomic theory of matter, stating that matter is not improved or denied, it just changes Fetus. -
Charles-Augustin deCoulomb
He lived from 1736-1806 and was born in Agouleme, France. He made his discovery in 1785, which was the inverse square law of attraction and repulsion of unlike and like magnetic poles. -
Sir Isaac Newton
Lived from 1642-1727, born in Woolsthorpe, Lincolnshire. Made his discovery in 1666 which formulated a theory of light, the three laws of motion, and suggested a mechanical universe with small, solid masses in motion. -
John Dalton
He lived from 1766-1844. He was born in Eaglesfield, England. He made his discovery in 1803 which stated that all matter was composed of small indivisible particles termed atoms, atoms of a given element possess unique characteristics and weight, and three types of atoms exist: simple, compound, and complex. -
Michael Faraday
Lived from 1791-1867, born in Surrey, England. He made his discovery in 1821 and he contributed to the fields of electromagnetism and electrochemistry. -
Julius Plucker
Lived from 1801-1868 and was born in Elberfield, Germany. He made his discovery in 1833 and he showed that there is a relationship between matter and electricity. -
Dmitri Mendeleev
His lifespan lasted from 1834-1907 and was born in Tobolsk, Siberia. He made his discovery in 1869. What he contributed was the first periodic table. -
James Clerk Maxwell
Born in 1831, died 1879. His birthplace was Edinburgh, Scotland. He made his scientific discovery in 1857. He also created the first color photograph, the idea that light was an electric phenomenon, and the discovery of radio waves. -
George Johnstone Stoney
George, being born in Oakley Park, Ireland, lived from 1826-1911. He made his discovery in 1894 and introduced the term electron and estimated the charge carried by a single hydrogen atom. -
Sir William Crookes
He lived from 1832-1919. He made his discovery in 1861. He contributed research on electrical discharges through a rarefied gas. He demonstrated that cathode rays travel in straight lines and produce phosphorence and heat when they strike certain materials. -
Eugen Goldstein
Lived from 1850-1930, being born in Gliwice, Poland. He made his discovery in 1886. He noted that cathode-ray tubes with a perforated cathode emit a glow from the end of the tube near a cathode. -
Wilhelm Roentgen
Lived from 1845-1923, born in Remscheid, Germany. He made his discovery in 1895, discovering x-rays. -
Henri Becquerel
Lived from 1852-1908. Born in Paris, France. Made his discovery in 1892. He discovered radioactivity in uranium. -
Joseph John Thomson
He lived from 1856-1940. Born in Manchester, England. Made his discovery in 1897. He discovered the electron. -
Ernest Rutherford
Lived from 1871-1937. He was born in Nelson, New Zealand. He made his discovery in 1914. He discovered the nucleus, neutron, and proton of the atom. -
Marie Curie
Lived from 1867-1934, born in Savoy, France. He made his discovery in 1898. She invented two new elements, radium and polonium. -
Max Planck
Lived from 1858-1947. He was born in Kiel, Germany. He made his discovery in 1900 and he discovered the quantum theory. -
Albert Einstein
Lived from 1879-1955. He was born in Wurttemberg, Germany. He made his discovery in 1915. He discovered the law for energy, general theory of relativity, and special theorty of relativity. -
Robert Millikan
Lived from 1868-1953. Born in Morrison, Illinois. Made his discovery in 1909. He discovered the mass and charge of the electron. -
Frederick Soddy
Lived from 1877-1956. Born in Eastbourne, England. He made his discovery in 1912. He researched radioactivity decay and proposed a theory of isotopes. -
Erwin Schroedinger
Lived from 1887-1961, born in Vienna, Austria. He made his discovery in 1937 and determined how to find the probability for where the electron is an atom. -
Niels Bohr
Lived from 1885-1962. He was born in Copenhagen, Denmark. He made his discovery in 1913. He discovered that the electrons move in orbitals around the nucleus. -
Werner Heisenberg
Lived from 1901-1976. Born in Wurzburg, Germany. Made his discovery in 1927 when he discovered a way to formulate a quantum mechanics in terms of matrices. -
James Chadwick
Lived from 1891-1974. He was born in Bollington, England. Made his discovery in 1932. He discovered that the atom was made up of a central nucleus surrounded by fast moving electrons. -
Small, spherical, solid, indivisible model
The small, spherical, solid, indivisible model of the atom created by Democritus is shown above. Basically, this model is the basis of the origional thought view of the atoms. This model is what Democritus believe the universe was made up of. He thought the world was made up of empty space and an infinate amount of atom. Through this model, you can notice how basic this atom is viewed as due to the lack of any legitament knowledge of the atom during this time period. However, this is what Democ -
Electron Cloud Model
Date developed: 1927. The electron cloud model is an atom model wherein electrons are no longer depicted as particles moving around the nucleus in a fixed orbit. Instead, as a quantum mechanically-influenced model, we shouldn’t know exactly where they are, and hence describe their probable location around the nucleus only as an arbitrary. -
Plum Pudding Model
Date developed: 1904. The Plum Pudding Model is a model of atomic structure proposed by J.J. Thomson in the late 19th century. Thomson had discovered that atoms are composite objects, made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom. He therefore proposed that atoms have structure similar to a plum pudding, with tiny, negatively charged electrons embedded in a positively charged substrate. -
Rutherford-Bohr Model
Date developed: 1913. A simple definition of Bohr’s atomic model is: electrons orbit the nucleus at set distances. When an electron changes orbits, it does so in a sudden quantum leap. The energy difference between the initial and final orbit is emitted by the atom in bundles of electromagnetic radiation called photons. -
Planetary Model
Date developed: 1913. The planetary model is the most familiar model or illustration of the structure of the atom. Since the ancient Greeks physicists agreed that the atom existed. However it was believed to be the smallest cohesive unit of matter until the experiments of J.J Thompson and later Rutherford B. Hayes in the early 20th century. The model gave modern physicists their current understanding of the atom and the particles that its composition consists of. -
Ancient
2560 BC: Building of the Great Pyramid of Cheops at Giza.
1795-1750 BC: Hammurabi, who wrote the first legal code, conquered Mesopotamia, the land between the Tigris and Euphrates Rivers.
995 BC: Hebrew King David captured Jerusalem. -
500-1800
1066: Battle of Hastings
1100-1300: Crusades
1215: Signing of the Magna Carta -
1800-1875
1800: Napoleon conquers Italy
1801: Austria makes temporary peace with France
1803: US negotiates Louisiana Purchase from France -
1875-1900
The first commercial telephone exchange is made in New Haven, Connecticut during 1878First electrical power plant and grid in Godalming, Britain esatblished in 1881The U.S. gains control of Cuba, Puerto Rico, and the Philippines after the Spanish-American War in 1898 -
1900-1915
Einstein revolutionizes physics in 1905Russian Revolution of 1905Titanic sinks in 1912 -
1915-1950
Robert Goddard makes the first flight of a liquid-fueled rocket in 1926Atomic bomb is dropped on Hiroshima in 1945Korean War begins in 1950 -
1950-2012
Hubble Telescope is launched in 1990World Trade Centers attacked in 2001Red Sox win first World Series title since 1918
