How Has The Periodic Table Changed

In this research paper, I’m going to talk about how the Periodic Table has changed over the years. It has changed in many ways, but it still has some similarities in it. There has been many scientist that had contributed to the development of the Periodic Table. A few of those scientists are Johann Dobereiner, John Newlands, and Julius Lothar Meyer. Although Dmitri Mendeleev had been given the credit for the development of the first Periodic Tables, these scientist deserve recognition as well. There also had been several changes to the 1869 Periodic Table and the scientist that contributed to that as well were, William Ramsay, Henry Moseley, and Glenn Seaborg. Dmitri Mendeleev was a Russian chemist who formulated the Periodic Table. Mendeleev

Dobereiner was the founder of the different trends founded in the Periodic Table, for example the average atomic mass of Lithium is close to the average atomic mass of Sodium. The different trends seemed to follow a similar pattern and soon enough became known as ,” Dobereiner’s Traids”. The atomic weight of the middle elements in each traid is equal to the average of the atomic weights of the first and third elements. He started to group elements with similar chemical characteristics. During the 1820’s, Dobereiner’s experiments with hydrogen led J.J Berzelius to the creation of catalyst. He also figured out that the properties of bBromine seemed to be halfway between chlorine gas and sodium iodine. Johann founded organic compounds such as furfural, and developed the separation of elements such as calcium and

Meyer stated if each element is arranged in order of their atomic weights, and fall into groups of similar chemical and physical properties. If the atomic weights were plotted as ordinates and the atomic volumes as abscissae, the curve obtained a series of maxima and minima. The most electropositive elements appear at the peak of curve in order of their atomic weights. One contribute Meyer had was the concept that carbon atoms in benzene were arranged in a ring. Except, he didn’t propose the alternation of single and double bonds, that was included later in a structure by August