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The Discovery of Oxygen
On August 1, 1774, Joseph Priestly discovered oxygen by heating mercury and studying the gas it produced. He first called the gas "dephlogisticated air," but the name was later changed to oxygen. Oxygen is the 8th element on the periodic table of elements History.com Staff. "Joseph Priestley Discovers Oxygen." History.com. A&E Television Networks, n.d. Web. 13 July 2017. Jefferson Lab Staff. "It's Elemental." The Element Oxygen. Jefferson Lab, n.d. Web. 13 July 2017. -
Atomic Theory
The atomic theory is the theory that all matter is made up of tiny indivisible particles called atoms. The atoms of each element are identical, but differ from atoms of other elements. John Dalton's atomic theory was the first attempt to explain matter in small terms and their properties. Khan Academy Staff. "Dalton's Atomic theory." Khan Academy. Khan Academy, n.d. Web. 13 July 2017. -
Electricity Transforms Chemicals
Humphry Davy was a scientist that used a battery for what is called electrolysis and was able to separate many substances for the first time. He was able to separate these elements using electrochemistry. This proved that electricity could effect chemicals. BBC Staff. "History - Sir Humphry Davy." BBC. BBC, 2014. Web. 13 July 2017. -
Synthesis of Urea
The synthesis of urea was discovered by Friedrich Wohler. He was conducting experiments with two inorganic elements. A white, powdery crystal was formed. He noticed that this crystal was also formed from two organic elements. This proved that there wasn't as much of a difference between inorganic and organic chemicals as had been previously thought. 100 Discoveries of Chemistry: Episode 3. N.d. Youtube. DevTester, 29 Mar. 2014. Web. 13 July 2017. -
Atoms Have Signatures of Light
Studies and experiments showed that each metal emitted a unique light or color when heated in a flame. The flame changed color, allowing scientists to determine what was in the compound based on the color that the flame changed. Kim Rendfeld. "The Colorful Signature of Each Element." Kim Rendfeld. N.p., 07 Oct. 2014. Web. 13 July 2017. -
Chemical Structure
August Kekulé, a scientist, focused his attention on a molecule, carbon-60, that didn't follow the chemical structure theory. He dreamed of chains of molecules and a snake that grabbed its own tail. He woke up and organized the long chain of carbon in a circle, allowing it to follow the pattern set by other chemical structures and fulfilling the chemical structure theory. Famous Scientist Staff. "Friedrich August Kekulé." Famous Scientists. Famous Scientists, n.d. Web. 13 July 2017. -
Periodic Table of Elements
Chemist Dimitri Mendeleev was working on writing a textbook when he wanted to find a better way to organize the elements. He wrote down the elements on cards and organized them by atomic mass. He noticed that there was a pattern every seven elements. He grouped elements based on their properties and was even able to predict three elements that hadn't been discovered yet. Lenntech Staff. "Periodic Table History." Lenntech. Lenntech, n.d. Web. 13 July 2017. -
Radioactivity
Henri Becquerel was studying x-rays when he stumbled upon the discovery that uranium emitted radiation without an external source of energy. Marie Curie and her husband later continued the experiments, discovering two more elements that were more radioactive than uranium. Rutherford later studying radioactive decay. "The Discovery of Radioactivity." The Discovery of Radioactivity. N.p., 9 Aug. 2000. Web. 13 July 2017. -
Electrons
A scientist named J.J. Thomson discovered the first sub-atom particle: the electron. All atoms are made up of a nucleus and electrons. Chemicals are bonded through electron interactions and exchanges. Electrons are negatively charged and orbit the nucleus. "The Electron Discovery Experiment." Nobelprize.org. N.p., 2017. Web. 13 July 2017. -
Plastics
Polymers are the building blocks of plastics. Polymers are very long molecules that are mainly made of carbon atoms. The shape of the polymers gives plastic its plasticity, allowing them to be easily molded. Knight, Laurence. "A Brief History of Plastics, Natural and Synthetic." BBC News. BBC, 17 May 2014. Web. 13 July 2017.
