Greatest Discoveries: Chemistry

Early scientists only believed there were four elements: Water, fire, earth, and air. However, Leonardi da Vinci changed that idea. Then, new chemists came along and figured out, that there is much more to Earth than those four elements. Joseph Priestley discovered the idea of oxygen, and how there is much more than just “air.” Then Antoine Lavoisier, in a way, made oxygen. Soon. John Dalton came along in the early 19th century, and found that elements must be made up of different elements, these elements are now known as atoms. He made his idea useful, and called it the atomic theory. The system was simple, but effective. Jospeh Gay-Lussac experimented to conduct the atomic theory. Amedeo Avogadro realized gases were made of multiple atoms, instead of just one. Dmitri Medeleev constructed a card for each element. He began putting each element in a specific area, making the elements closest together, similar. In this way, the periodic table was discovered. This discovery forever changed the meaning of elements. One day, Humphry Davy was constructing an experiment with pot ash. As he was melting the pot ash, he found it was melting into pure potassium. Soon, chemists started studying why substances emitted specific colors when placed in a flame. Then, chemists started building the very first spectra-scope. With the spectra-scope, chemists were now able to see spectrums of sodium in the sun. Joseph Thompson found the mass of an electron. He soon found a stream of rays and named it radiant matter. The ray was a stream of electrons. Soon, Gilbert Lewis explained how electrons travel throughout an atom. Henri Becquerel conducted an experiment to see which minerals were radioactive. He found Uranium to be the most radioactive. Marie curie carried on with his ideas, and discovered new radioactive minerals called polonium and radium. Ernest Rutherford found alpha and beta particles, and he also found gama rays. In the 1860’s, John Hyatt created the first plastic from plants. Leo Baekeland continued on with this idea. Harold Kroto, James R. Heath, Sean O’Brien, Robert Curl, and Richard Smalley found a special cluster of carbon atoms, which they named Bucky Balls. Soon, carbon nano-tubes were found. These tubes were 100x stiffer than steel. They call these carbon atoms a modern day industrial revolution. and, it will soon be possible to build things from scratch that are much stronger than things used today. Overall, chemistry changed the world.

Freezing and Melting of Water

Freezing and Melting of Water

If salt is put into ice water, then the water will freeze, because salt expands the freezing water causing more ice or cold water. When the freezing water is put into the warm water, it will melt.





<-- This shows how the water starts to freeze









This graph shows how the water freezes over time. As seen, the huge peak is shown after the water has become frozen. The water’s freezing point was -3.5.

This graph shows how the water melts over a period of time. The huge peak is when the frozen water is put into the hot water. The water’s elting point was1.6.

In the end, I accepted my hypothesis. The water became frozen while in the freezing water, and it melted after being put into the warm water. A problem that occured with our expirement was that we were stirring the salt, however we did not stir enough to make the salt fully dissappear. Some variables that could have differed this lab would have been putting a different amount of water in the water and putting a different amount of water in the test tube and beaker.