Chemistry’s Greatest Discoveries
Oxygen: In the 1800s, it was thought that air was one gas. Joseph Priestly thought differently, so he searched for new airs or gases. He heated mercury and a gas came off of it. This gas was oxygen.
Atomic Theory: John Dalton discovered that elements could be combined in infinite ways because there were smaller particles that made up elements. These particles are atoms. This discovery helped to get the ball rolling in chemistry.
Atoms Combine into Molecules: Joseph Louis Gay-Lussac was trying to study Dalton’s Atomic Theory. He found that gases produced twice the volume expected. Amedeo Avogadro found that gases weren’t made of single atoms like everyone thought. Atoms can be arranged into molecules. This enlightened the chemists of the time and allowed them to move out of the so called “Dark Ages.”
Synthesis of Urea: Friedrich Wohler combined inorganic materials found in urine. The synthesis of the substances silver cyanate with ammonium chloride made the crystal, urea.
Chemical Structure: Friedrich August Kekulé von Stradonitz wrote atoms out with letters and lines showing their attractions to other atoms. Benzene was the only atom that didn’t fit the formula. A man thought about a snake biting its own tail, and this lead him to discover that the formula for Benzene is this:
Periodic Table of Elements: Dmitri Mendeleev discovered the periodic table when he was making a lesson plan for his students. He was using flashcards for the elements and he arranged the elements in different orders. Eventually, he found a pattern. He predicted certain elements and made the periodic table. Element 101 on the periodic table is named Mendelevium after him.
Electricity Transforms Chemicals: Humphry Davy conducted experiments with batteries and hot ash over electricity. He found that the hot ash let off pure potassium. This allowed him to come to the conclusion that electricity can alter chemicals.
Atoms Have Signatures of Light: If chemicals are mixed with fire, then the fire turns different colors. Copper makes fire shades of green which is what you see in the picture below. Kiracofe was reminded that prisms spread light. He used a spectroscope and it worked. Each element produced unique colors. Bunsen and Kiracofe discovered 2 new elements, Cesium and Rubidium. They tried this experiment on the sun and they found sodium on the sun! This technology is used to search planets for signs of water even today.
The Electron: Joseph Thompson did an experiment to find the charge and mass of an element. He was a professor at the time and he used a cathode-ray to conduct his experiments. He connected the 2 ends of the apparatus, and electrons were seen. Magnets were used to deflect or bend the electrons.
Electrons Form Chemical Bonds: In the early 1900s, Gilbert Louis developed a model of the atom. He discovered Valence Electrons and their ability to transfer electrons to other atoms. This allowed new compounds to be made.
Radioactivity: Henri Becquerel tested minerals and he coincidentally tested uranium. He was able to prove that he found the source of radioactivity. Marie Curie further tested uranium and she isolated 2 elements found in uranium. Her discoveries killed her because she had been in so much contact with radiation. Ernest Rutherford discovered that radioactive materials decay and let off dangerous particles over time. Radioactivity is not all bad though, it allows us to treat patients with cancer, investigate and understand the earth, and so much more.
Plastics: John Wesley Hyatt found a way to exploit strings of atoms in plants. Leo Baekeland made Bakelite. He found the first fully synthetically created plastic. Polymer makes plastic and polymer are made of long strings of atoms. We use plastic in so many things all the time today and in all the items you see below
Fullerenes: It's made of carbon nanotubes and is thinner than a strand of DNA. Richard Smalley, Robert Curl, and Harold Kroto won the 1996 Nobel Prize for Chemistry for their buckyball. They discovered 60 carbon atoms clumped together to make Fullerenes. Another man discovered new Fullerenes that make buckytubes. These are very strong molecules. They can stretch and they are quite marvelous. It is called a modern day Industrial Revolution.
Over 2 centuries we have come so far, and these amazing discoveries have changed chemistry forever and the world forever. We can see things in new ways, we can make new things, and the mysteries of the world are being put together piece by piece.
Periodic Table of Elements: Dmitri Mendeleev discovered the periodic table when he was making a lesson plan for his students. He was using flashcards for the elements and he arranged the elements in different orders. Eventually, he found a pattern. He predicted certain elements and made the periodic table. Element 101 on the periodic table is named Mendelevium after him.
Electricity Transforms Chemicals: Humphry Davy conducted experiments with batteries and hot ash over electricity. He found that the hot ash let off pure potassium. This allowed him to come to the conclusion that electricity can alter chemicals.
Atoms Have Signatures of Light: If chemicals are mixed with fire, then the fire turns different colors. Copper makes fire shades of green which is what you see in the picture below. Kiracofe was reminded that prisms spread light. He used a spectroscope and it worked. Each element produced unique colors. Bunsen and Kiracofe discovered 2 new elements, Cesium and Rubidium. They tried this experiment on the sun and they found sodium on the sun! This technology is used to search planets for signs of water even today.
The Electron: Joseph Thompson did an experiment to find the charge and mass of an element. He was a professor at the time and he used a cathode-ray to conduct his experiments. He connected the 2 ends of the apparatus, and electrons were seen. Magnets were used to deflect or bend the electrons.
Electrons Form Chemical Bonds: In the early 1900s, Gilbert Louis developed a model of the atom. He discovered Valence Electrons and their ability to transfer electrons to other atoms. This allowed new compounds to be made.
Radioactivity: Henri Becquerel tested minerals and he coincidentally tested uranium. He was able to prove that he found the source of radioactivity. Marie Curie further tested uranium and she isolated 2 elements found in uranium. Her discoveries killed her because she had been in so much contact with radiation. Ernest Rutherford discovered that radioactive materials decay and let off dangerous particles over time. Radioactivity is not all bad though, it allows us to treat patients with cancer, investigate and understand the earth, and so much more.
Plastics: John Wesley Hyatt found a way to exploit strings of atoms in plants. Leo Baekeland made Bakelite. He found the first fully synthetically created plastic. Polymer makes plastic and polymer are made of long strings of atoms. We use plastic in so many things all the time today and in all the items you see below
.
Fullerenes: It's made of carbon nanotubes and is thinner than a strand of DNA. Richard Smalley, Robert Curl, and Harold Kroto won the 1996 Nobel Prize for Chemistry for their buckyball. They discovered 60 carbon atoms clumped together to make Fullerenes. Another man discovered new Fullerenes that make buckytubes. These are very strong molecules. They can stretch and they are quite marvelous. It is called a modern day Industrial Revolution.
Over 2 centuries we have come so far, and these amazing discoveries have changed chemistry forever and the world forever. We can see things in new ways, we can make new things, and the mysteries of the world are being put together piece by piece.
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