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460 BCE
Democritus Facts
○ Democritus was commonly known as the "laughing philosopher". Not because his laughter is special in any way, but because he had a joyful spirit.
○ Democritus was born to a rich family (spoiled kid...) and he was very close to his father.
○ Not only is he a philosopher, he is also interested in Geometry and travelling.
○ His idea of an atom was commonly rejected at the time due to common beliefs to Aristotle's theory of 4 elements (Fire, Air/Wind, Water, and Earth) and religious reasons. -
Period: 460 BCE to 370 BCE
Democritus - A Greek philosopher and a student of Leucippus
Extending ideas of Leucippus (not really plagiarizing,) he stated "matter can't be infinitely divided". That is, when dividing matter, there has to be a point where remaining matter can't be divided further. This remain was named "A Tomos", meaning indivisible in Greek. This theory was the theory of Atomism. He also suggested that different matters are made of different particles with different properties, varying in size and shape. Yet, it is suspected that he took this credit from Leucippus. -
500
Medieval Alchemy Facts
○ Alchemists discovered at least 5 true elements: Arsenic, Bismuth, Zinc, Phosphorus, and Antimony
○ They also discovered many famous chemicals used in their experiments, such as nitric acid, acetic acid, and ammonium chloride.
○ The usual purpose of alchemy practices was to turn basic elements such as lead into gold.
○ Though Alchemy seems too scientific for religious groups, part of the alchemists are in fact religious groups trying to find miracles. -
Period: 500 to
Medieval Alchemy - changing one substance into another
Due to Aristotle's strong influence, alchemists believed that elements can be transformed to another using "philosopher's stone", a mysterious chemical that could alter nature of all substances. Though modern chemistry ideas gradually took over alchemy before 17th century, alchemy built the basic mechanism for chemistry. The alchemists set up labs and invented simple chemical techniques such as crystallization and distillation. They also sorted elements into the first conceptual periodic tables. -
Period: to
John Dalton - An English Quaker teacher, chemist, physicist, and meteorologist.
Dalton suggested that matters were made of small particles with empty spaces between each other. Atoms, according to Dalton, were "solid, indestructible spheres that had no internal structure." He also realized that compounds were always made of the same proportion of different particles, which is the correct idea. In 1803, he came up with the law of multiple proportions, suggesting the same elements combines in different ways to form different compounds. (continued) -
Period: to
John Dalton (continued)
(continued) He also worked out the system for atomic weights by observing relative weights of elements when in proportion of compounds. For example, he found that 1 gram of hydrogen always combined with 8 grams of oxygen to form water, and therefore believed that water was made up of 1 atom of hydrogen and 8 atom of oxygen. This was one of the very first idea about atomic mass. -
John Dalton's Law of Multiple Proportions published
This law was published in his book, "New System of Chemical Philosophy," and stated that same elements can combine differently to form different compounds. Also, the atomic weight idea was included in this book, which supported the Atomic theory.
LAW OF MULTIPLE PROPORTIONS
1. Element made of atoms
2. Same element = same particle
3. Different types of atoms = different properties
4. Can't create/destroy/split atom
5. In reaction, atoms links together/separates.
6. Atoms combine in ratios -
A fact from Quaker John Dalton: I hate awards, and I hate scarlet.
John Dalton was a Quaker and refused all recognition & ceremonial tribute for his achievements & contributions to Science. In 1810, when he was invited to be a member of the Royal Society, Dalton refused like he always did. In 1822, however, he was still elected to Royal Society without his own knowledge. Also, because John Dalton was colorblind, when he was eventually presented to the king for the award, he wore the "gray" robe which is actually scarlet, a forbidden color for Quakers. -
Period: to
Antoine-Henri Becquerel - radioactivity
Henri Becquerel, a French physicist, discovered radioactivity. He wondered if X-Ray is connected to the naturally occurring phosphorescence (emission of light after excitement stage). To test this, he put Uranium salt on a photographic plate covered with opaque paper. The plate became foggy, afterwards concluded as trait of Uranium atoms. Those gases ionized and could be deflected by electric fields, unlike X-ray. This is radioactivity, meaning that Uranium radioactively breaks down on its own. -
J.J. Thomson Facts
○ J.J. Thomson's father was a bookseller and always wanted Thomson to be an engineer, which was sort of similar to his career as a physicist in the future.
○ He was the professor of many famous scientists, such as Ernest Rutherford and Neils Bohr
○ Thomson was a respected and well-liked person
○ His wife, Rose Paget, was one of his students. -
Period: to
Joseph John Thomson (continued)
(continued) The mass of the electron was his most revolutionary finding, calculated based on the degree of curvature in the electron's path as it passed through the electromagnetic field. He described the shape of an atom as a "plum pudding," a sphere of protons with electrons embedded in the inside, which refined the atom ball proposed by Dalton. He also believed that the electrons were always arranged in a definite way unique to each element. -
Period: to
Joseph John Thomson - an English physicist studying discharge rays
J.J. Thomson studied discharged rays created from electrical discharge of cathodes in vacuumed discharge tubes. One time another scientist found out that the light can also be created from a positive electrode, indicating the presence of a positive ray. Thomson put this knowledge to research using physical concepts and was able to estimate the mass of the rays. He realized that those rays were made up of small very light particles, which he named corpuscles (electrons). (continued) -
Period: to
Marie Curie - the first women to receive Nobel Prize
Perhaps most commonly seen together with her husband Pierre, she was a great scientist who studied into Radioactivity that Henri Becquerel discovered, which she had given the name for. She conducted her own experiments on the Uranium rays and soon theorized that the rays came from the atomic structure of the element, since those rays were always constant & independent. Her husband soon paused his own project to aid her, and soon they discovered 2 new radioactive elements, Radium and Polonium. -
Ernest Rutherford Facts
○ He was the 4th of 12 kids in the family... WOW
○ His family was not very wealthy, so he invented ways to help his family's financial problem
○ When he was 10, he constructed a mini cannon from a science book which actually (surprisingly) exploded
○ He fell in love with his landlady's daughter and married in 1900 (Romantic) -
Period: to
Earnest Rutherford (continued)
(continued) After discovering alpha ray, he used it to bombard a very thin sheet of gold foil to support the structure of atom that his teacher, J.J. Thomson suggested. The result was surprising, because not all of the alpha particles went straight through the foil. Some of the particles were deflected and scattered. Therefore, he concluded that an atom is mostly empty space with a dense core. This is the planetary model of atom, suggesting orbiting electrons around a dense nucleus with protons. -
Period: to
Ernest Rutherford - Father of Nuclear Age
Earnest Rutherford was the first person to suggest that alpha, beta, and gamma rays were products of decaying atoms. He discovered 3 kinds of rays, one of them attracted to a negative terminal, indicating a positive ray made of particles, which were then named as alpha rays. The other ray attracted to positively charged electrodes were named beta rays with electron-like properties. The last ray was the strongest penetrating ray that was not bent by the field, named gamma ray. (continued) -
Period: to
Niels Bohr - A Danish Scientist well known by all high school students who had to suffer Science 10.
Niels Bohr's most famous contribution to chemistry is the Bohr's model, in which he theorized electrons traveled in orbits around the nucleus. Bohr's atomic model also considered that the electrons could jump from one orbit to another, while each orbital has a certain amount of electrons in it. This atomic model is the planetary model, showing the electrons circulating the nucleus. He also concluded that when those electrons jump, they created energy and therefore was mechanism of radiation. -
Period: to
Sir James Chadwick - an English pysicist who discovered the neutron
After discovery of electron & proton, everyone new that the left over mass in the atomic nucleus has to be caused by an unknown particle. It was very hard to find, though, because it's not charged and therefore impossible to detect. Chadwick had a solution. In 1932, he bombarded the metal beryllium with alpha particles and had evidence that a neutral particle spread out from the beryllium. He named this newly discovered neutral particle the neutron. (continued) -
Period: to
Sir James Chadwick (continued)
(continued) Not only that, since he discovered the neutron, he also significantly helped other scientists solve the ultimate mystery of atomic mass. All scientists knew that the atomic number is the number of protons and is also the number of electrons of an atom in a normal state, but the total atomic mass never adds up right. The existence of neutrons proved that it is possible to have the same charge yet an increased atomic mass which also determines the isotopes the elements are in. -
J.J. Thomson discovered the first electron while working with a discharge tube!
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Henri Becquerel Facts
○ In 1903, one special Nobel Prize of Physics was given to 3 people for the same award: Becquerel, Pierre Curie, and his wife Marie Curie. They shared the awards, not because they are friends (they could be, but there are no references), but because the Curie couples studied and modified details of radioactivity. As a result, since Henri discovered radioactivity and the Curie's studied radioactivity, the prize was divided into 4th: Henri got 2/4, and each of the Curie couple got 1/4. -
Marie Curie - Facts
○ Marie Curie was the first women to receive Nobel Prize, and she was the only women who has ever received 2 Nobel Prizes in 2 different fields (physics in 1903 and chemistry in 1911)
○ After her husband Pierre Curie's death in 1906, she still had to take over his teaching post at the Sorbonne, becoming the institute's first female professor "accidentally"
○ Curie's death is well-known - she always carries radium samples in her pocket, and she died of aplastic anemia in 1934 due to radioactivity -
Pierre Curie Facts
○ While most people know how his wife Marie had died, only a few looked into Pierre's death. His death was an accident, ran over by a horse-pulled wagon, and was a tremendous loss to his wife Marie Curie.
○ Pierre Curie was born on May 15, 1859. Though he went to university, he lacked money to continue school after earning a degree in Faculty of Sciences, so he worked as a lab instructor until he could return.
○ His scientific partners were not only Marie Curie, but also his brother Jacques. -
Niels Bohr Facts
○ He was the student of J.J. Thomson, who was another very famous physicist.
○ Won the Nobel price in Physics in 1922 for his work on atomic structures
○ Had 6 children, but only 4 survived to become adults. RIP. -
Sir James Chadwick Facts
○ When he went to university, Chadwick originally wanted to be registered in the mathematics program, but mistakenly was registered into the physics program. (It was not the receptionist's fault. He waited in the wrong registration area.) He did more than fine despite the mistake.
○ He discovered the neutron during an investigation of beryllium disintegration, somewhat copying the same research method of his teacher/lab boss J.J. Thomson.
○ In 1935, he was awarded the Nobel Prize in Physics. -
Period: to
Bibliography Part 1
C. (n.d.). ChemTeam: Atomic Structure - Greeks. Retrieved November 29, 2016, from http://www.chemteam.info/AtomicStructure/Greeks.html
E. (2010, December 1). Democritus. Retrieved November 29, 2016, from https://the-history-of-the-atom.wikispaces.com/Democritus
Ross, S. (2016, October 26). John Dalton. Retrieved November 30, 2016, from https://www.britannica.com/biography/John-Dalton
Goldstein, N. (2001). How do we know the nature of the atom? New York: The Rosen Publishing Group, Incorporated. -
Period: to
Bibliography Part 3
T. (2015, July 27). [J. J. Thomson in his laboratory]. Retrieved December 1, 2016, from http://www.famousscientists.org/j-j-thomson/
[Quote of Ernest Rutherford]. (n.d.). Retrieved December 1, 2016, from http://www.azquotes.com/quote/530282
B. (2014, April 01). Ernest Rutherford Biography. Retrieved December 02, 2016, from http://www.biography.com/people/ernest-rutherford-39099
[Niels Bohr Quotes]. (n.d.). Retrieved December 1, 2016, from http://www.azquotes.com/quote/30770 -
Period: to
Bibliogrphy Part 4
B. (2013, May 14). Niels Bohr. Retrieved December 02, 2016, from http://www.biography.com/people/niels-bohr-21010897
The Contributions of Neils Bohr to Chemistry. (n.d.). Retrieved December 02, 2016, from http://www.actforlibraries.org/the-contributions-of-neils-bohr-to-chemistry/
[Antoine Henri Becquerel]. (1903). Retrieved December 1, 2016, from http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/becquerel-bio.html -
Period: to
Bibliography Part 5
The Nobel Prize in Physics 1903. (n.d.). Retrieved December 02, 2016, from http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/
P. (n.d.). Henri Becquerel [Digital image]. Retrieved December 1, 2016, from https://www.britannica.com/biography/Henri-Becquerel
B. (2015, November 20). Marie Curie. Retrieved December 02, 2016, from http://www.biography.com/people/marie-curie-9263538 -
Period: to
Bibliography Part 2
Democritus Quotes (Author of The Atomists Leucippus and Democritus). (n.d.). Retrieved December 01, 2016, from https://www.goodreads.com/author/quotes/2751823.Democritus
Law of multiple proportions [Digital image]. (2004). Retrieved December 1, 2016, from http://wps.prenhall.com/wps/media/objects/602/616516/Media_Assets/Chapter02/Text_Images/FG02_02.JPG
B. (2014, April 01). J.J. Thomson Biography. Retrieved December 01, 2016, from http://www.biography.com/people/jj-thomson-40039 -
Period: to
Bibliography Part 6
[Pierre Curie - Facts]. (n.d.). Retrieved December 1, 2016, from http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/pierre-curie-facts.html
[Marie Curie]. (2016, March 01). Retrieved December 1, 2016, from https://www.howitworksdaily.com/heroes-of-science-marie-curie/
S. (2014, March 06). [James Chadwick]. Retrieved December 1, 2016, from http://www.huffingtonpost.com/2014/06/03/james-chadwick-nobel-discovery-neutron-auction_n_5438512.html -
Period: to
Bibliography Part 7
Fosmire, M. J. (2016). James Chadwick. Retrieved December 02, 2016, from http://www.chemistryexplained.com/Ce-Co/Chadwick-James.html
