Over the ages, more ideas were formed ab expose what each matter is do of. The ancient Greeks believed there to be altogether four ingredients- air, earth, fire, and water. We nowadays know that elements are the simplest type of a pure substance. Because of the some(prenominal) varied properties of elements, they have been organized in stacks of different ways. Dmitri Mendeleev devised the periodic card that we use today. He lined up all of the known elements and then put them in change magnitude crop by atomic mass, deviation room for those that he ringed were missing. There were some errors in Mendeleevs periodic defer, however. When the elements are set in state of change magnitude atomic mass, several elements appeared out of place. Years later, Henry Moseley, a British scientist, discovered the atomic number of elements, and everything fit by rights in the periodic table when they were placed in order by increasing atomic number. Mendeleev knew that there w ere gaps in the table because some elements that were next to distri plainlyively other didnt share common properties. He was able to predict the properties of the missing elements by looking at the properties of elements next to them and the elements that were in the same family. registered nurse was discovered in 1900. This element was discovered Friedrich Ernst Dorn.
He discovered it in Germany piece he was studying the celestial longitude decay chain. The most rife isotope of this element is Radon-222, which is formed by the radioactive decay of radium-226. Since this element is radioactive, there arent very many uses for it. During the 1950s, radon was used in luminous paint of th e numerals of clocks, but when it was found ! to be radioactive in 1962, those clocks were recalled. Radon is also used in the treatment of cancer. It is currently... If you want to formulate a full essay, order it on our website:
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