It all started with the discovery of Oxygen. Before Oxygen was discovered ancient Greek philosophers thought that there were four elements. Air, water, earth, and fire. They believed that air was the underlying element. Leonard Da vinci was one of the first too suggest that air might be made of two different gases.
During the later part of the 18th century, Joseph Priestley did an experiment that emitted oxygen. He didn't know exactly what he had found. In 1774 Antoine Lavoisier repeated the experiment and weighed things. He found that it emitted oxygen, and then he created a list of elements.
John Dalton learned from experimenting that you could combine elements in definite and constant proportions. He thought that the elements were made of smaller pieces of matter. He called them Atoms. He developed the Atomic Theory, which is the relationship between atoms and the elements. It was a simple and effective rule.
During the early 1800s, Joseph Gay-Lussac found that when he combined different gases, the resulting weight was often twice what he predicted. In 1811 Amedeo Avogadro put out the idea that gases might be made of more than one atom. He called them molecules.
During the 19th century, it was common belief that organic substances and inorganic substances were completely different. In 1828, Frederick Waller put two inorganic substances in a beaker by accident. They were potassium cyanate and ammonia sulfate. When he looked back at the beaker, it contained urea crystals. He had studied organic crystals that were exactly the same.
Atoms are usually combined with fixed ratios. August Kekule made a system for the structure of various molecules. Each had the letter that represented the element surrounded by the ways they could connect to others. The only element that would not fit his method was Benzene. Benzene has six hydrogen and six carbon atoms. One night he fell asleep by the fire and had a dream about a snake that caught its own til and formed a ring. When he woke up he tried the idea with Benzene and it worked.
In 1869 Dmitry Mendeleyev was writing a chemistry textbook for his students. He was trying to figure out how to best present the elements to his students. He wrote the elements on some cards and their atomic weights and other stuff. He started to rearange them until he had them sorted by physical and chemical appearence. The chart he came up with is what we now call the periodic table of the elements. He noticed three holes in the chart and was able to predict what elements they would be like. Later people discovered the elements he predicted and they were true. They named the element mendelevium after him.
At the turn of the 19th century people were connecting batteries to just about anything to see the results. Scientists thought that pot ash was made of multiple elements, but up until that point they couldn't prove it. Humphrey David melted pot ash and decided to attach it to a battery. When he connected the wires from the battery to the pot ash it started to bubble. Pure potassium started to emerge. This led to the rise of the aluminum industry.
When an element or substance is added to fire, it produces certain colors. For exmple, if you add copper to a flame it make the fire turn green. Sodium turns the flame yellow. Robert Bunsen and his research collaborator Gustav Kirchhoff decided to use a prism and found that when each element is placed in a flame it produces a spectrum. They looked at the sun through their contraption and found that two of the lines in its spectrum matched the lines in sodium. They found out that the sun has sodium in it. They also discovered 2 new elements.
Joseph Thomson discovered the electron. He extracted a small peice of an atom. He used a crook's tube. When you connect it to a battery, you can see a blue stream between the ends of the tube. You can use a magnet to bend the stream. One of his students was able to prove there was a a positive charge to balance the negative.
In the early 1900s, Gilbert Lewis made a model of an atom. He showed how electrons traveled in shells around the nucleus. For example, sodium and chlorine are dangerous on their own, but when a sodium atom gives up an electron and a chlorine atom accepts it, you get a compound we call table salt. Compounds shape our modern life.
In the 1890s people discovered x-rays and were trying to find where it came from. In 1896, Henri Becquerel conducted an experiment to see if certain minerals emitted radiation. Uranium was one element that worked. Marie Curie took up the job of isolating what created radiation. She managed to isolate polonium and radium. She concluded that radium was 1 million times more radioactive than uranium. She is believed to have died of radiation poisoning. Even today her notebooks are considered to radioactive to handle. Radio activity is highly charged particles that are emitted as the element decays.
In the 1860s, John Hyatt found a way to create plastic. 50 years later Leo Baekeland made Bakelite. he discovered the world's first fully synthetic plastic and it changed the course of the century. Plastic and synthetics mimic and even surpass organic made items. Plastics/polymeres are the basis of our society.
In 1985, Richard Smalley, Robert Cole, and Harold Crotone discovered "buckyballs." "Buckyballs" are a special cluster of carbon atoms that only want to have 60 atoms. When offered another atom, they don't accept anymore. They started calling them fullerenes. They were the extremely stable. Sumio Iijima discovered "buckytubes" or what we now call nanotubes. Nanotubes can extend to great lengths. they are like "buckyballs" except they are in a tube shape. "Buckytubes" are the stiffest material in the universe. Scientists guess that nanotubes are 100 times stronger than steel. They could change the works of our society.
