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460 BCE
Democritus
Born: 460 BC Abdera, Greece
“The Laughing Philosopher”
Contribution to the Atom:
He stated all matter is made up of atoms and that atoms are eternal, invisible, and so small they can not be divided. Also stated that they fill up space they are in entirely.
“Sea Shell Experiment”
He took a seashell and kept breaking it apart until left with a fine powder, he tried to take smallest piece of powder but could not, he called this the “indivisible building block of life called an atom -
460 BCE
Democritus
Democritus also studied astronomy, zoology, botany and medicine. He has written over 70 pieces, but none were cherised. -
Antoine Lavoisier
Came up with formula for the conservation of matter in chemical reactions.He also discovered the difference between an element and a compound. The Law of Conservation of Mass
Lavoisier's Experiment:
Heated mercury for 12days, red oxide of mercury was formed and he noticed ⅕ of air was used, he named the remaining gas, azote (now known as nitrogen). He used the remaining red oxide and heated again and got same volume of gas that disappeared last time. The discovery of the Conservation of Matter. -
Antoine Lavoisier
Born August 26, 1743 to May 8, 1794 in Paris,France
Anti-royalty was common, and Lavoisier was falsely accused. He was executed by guillotine. -
John Dalton
John was awarded the Royal Medal. He had a very rare colorblindness which only allowed him to see the color yellow. He also studied meterology. -
John Dalton
Born: Born: September 6, 1766- July 27, 1844 in the United Kingdom
Said matter is a spherical solid atom which is made up of small, indestructible particles called atoms that are all alike and have same atomic weight.The experiments he did were; the Law of Conservation of Mass:the total mass of chemicals does not change in a chemical reaction.
•The Law of Definite Proportion: to form compounds, elements combine in certain proportion by mass.
•The Law of Multiple Proportions -
J.J Thomson
Thomson published many papers and became Master of Trinity College until he died. -
Max Planck
Planck was appointed Dean of Berlin University. His home was destrpyed by Allied bombs and all his research was gone. -
Marie Curie
Marie Curie was the first woman to win a Nobel Prize and the only one to win in two different fields. She died from her careless practices around radiation and not taking the proper safety precautions. She is a Scorpio. -
Robert Millikan
Millikan was a tennis and golf player. He also had three sons. -
Ernest Rutherford
Rutherford was president of the Royal Society before becoming president of the Academic Assistance Council. -
Albert Einstein
Einstein did not want to join the military. He played the violin. He left school without notice by using a doctor’s note and went to Italy -
Niels Bohr
Bohr won a gold medal from the Royal Danish Academy of Sciences and Letters. His papers were published in 1913. -
Erwin Schrödinger
He and his wife escaped to Italy at the rise of the Nazi party in Germany after angering officials with his open opposition of the party. From Italy, they escaped to England where he held positions at Oxford and Ghent. He and his wife had no children, but Schrödinger fathered two children by two different women while living in Dublin. A moon crater is named after him. -
James Chadwick
His parents were poor, so he could not afford private grammar school but passed the exams for two university scholarships.When World War I started he was a prisoner at the Ruhleben Internment camp near Berlin. -
Louis de Broglie
Broglie wrote several pieces on the philosophy of science and the value of scientific discoveries. He was appointed as a member of the Academie des sciences and on October 12, 1944 he was elected to the Academie francaise. -
J.J. Thomson
Born: December 18th,1856- August 30th,1940 in United Kingdom
Discovered that the solid ball model was not correct because there was also negative charged atoms too (electrons).
The experiments he did were;
Cathode Ray Tube Experiment
- Gave atom model its electrons calling it the Plum Pudding Atomic Model.
-Claim atom was similar to a chocolate chip cookie -
Marie Curie
Born: November 7th,1867-July 4th,1934 in Warsaw, Poland
With her husband, they explored radioactivity. She discovered elements Radium and Polonium.
In her experiments, she worked ith radiation, she isolated radium. -
Max Planck
Born: April 23rd,1858-October 4th,1947 in Kiel Germany
He created the Quantum Theory. Stated that energy was given off in small things of energy. Discovered that the energy form is restricted to specific amounts. This led to ebergy levels in atoms. -
Werner Heisenberg
In 1941 he became Professor of Physics at the University of Berlin and Director of the Kaiser Wilhelm Institute for Physics.
He was captured by American troops during World War II and sent to England. -
Albert Einstein
Born: March 14th,1879-April 18th,1955 in Ulm Germany
Created the theory of relativity. He made the law of mass - energy equivalence through his formula, E=mc^2.
Through the Brownian motion experiments, he concluded his research. -
Robert Millikan
Born: March 22nd,1868-December 19th,1953 in Morrison Illinois
Determined the electric charge of a single electron.
"Oil Drop Experiment"
- He put a charge on a tiny drop of oil and mesured how strong an elecrtric field had to be tp stop the falling of oil. -
Ernest Rutherford
Born: August 30th,1871-October 19th,1937 in Brightwater, New Zealand
He thought the center of an atom was positively charged and the electrons were surrounding the nucleus. He called the particles in the center Protons
To prove this, he used alpha particles as atomic bullets, probed the atoms in a piece of thin gold foil. -
Niels Bohr
Born: October 7th,1885-November 18th,1962 in Copenhagen, Denmark
He explained that electrons in atom act like planets revolving around the sun. based this off of gravity rules
He created the Planatary Model
- electrons orbit nucleus without losing energy
electrons could only move in fixed orbits
- electons wih low energy are closer to nucles -
Louis de Broglie
Born: August 15th,1892-March 19th,1987 in Dieppe, France.
He confirmed the discovery of the electron
Broglie's Vision of Atom
-Developed wave mechanics theory
- Waves produced by electrons contained in the orbit set up standing wave of a certian energy, frequncy, and wavelentght -
Werner Heisenberg
Born: December 5th,1901-February 1st,1976 in Würzburg, Germany
Created matrix mechanics and discovered the Uncertainty Princible, which said that electrons do not travel in specific orbits. He also calculated the behavior of subatomic particles in an atom.Discovered electrons have photons. -
Erwin Schrodinger
Born: August 12,1887-January 4, 1961 in Vienna, Austria.
He thought that electron location could not be calculated and said they were waves of electrons.
"Electron Cloud Model"
-Electrons move in waves randomly
-subshells, mulipule layests in each energy shell -
James Chadwick
Born: Oct.20th, 1881-Jul.24th,1974 in Bollington, United Kingdom.
Discovered the neutron using alpha particles with a mass close to a proton.
