There has been amazing advancements in science over the years. To begin, Joseph Priestly discovered oxygen in England. He used mercury as a liquid metal to help discover gases. This man discovered oxygen and helped create the elements we still use today. Next, John Dalton also had a great discovery called The Relative Weights of Ultimate Particles. When it went public he called it Atomic Weights. Also, he developed the Atomic Theory which showed the relationship between atoms and electrons. Thirdly, Joseph Gay-Lussac noticed that gases produced twice the volume he expected. Amedeo Avogadro soon realized that gases had many atoms known as molecules. Also, August Kekule developed a system to help visualize the chemical structure of molecules. He developed a simple yet elegant system. The chemical Benzene had ruined his system. Kekule soon explained it as a ring, solving his problems. Next, Dimitri Mendeleev made a card for each element, for his students, and facts about about each element. This lead him to creating the Periodic Table of Elements. This changed how everyone would learn the elements. In addition, Humphry Davy discovered that electricity reacting with chemicals can transform them. Next, Joseph Thompson used a crooks-tube in the experiments. The stream of electrons bends to magnets. Next, Gilbert Louis explained that electrons and atoms went in shells around the nucleus. A shell can only contain a certain amount of electrons. Two chemical elements might form a compound when they give up or accept electrons from the shells. X-rays were founded in the early 1890's. This radioactivity changes daily life. It powers space crafts, it lets doctors see inside of you, it can cure tumors, it triggers fire alarms, and it lets us tell how old Earth is. Chemists changed the look and feel of the material world. Also, John Hyatt created plastic. Advancement is a good word. A word that means too many things altogether, yet it is what happens every day. Things come and go. These are only a few of what things are to be discovered.