Dmitri Mendeleev : The Periodic Table Of The Elements

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The periodic table of the elements was published in 1869 by Dmitri Mendeleev. He shows the elements in order according to the atomic weight. A pattern where similar properties for elements occur periodically. With the work of of the physicist Henry, the periodic table was known on the basis of increasing atomic number rather than an atomic weight. This table can be used to predicts the properties of elements that had not been discovered yet. It lists elements, in other words number of protons in every atom. Elements are arranged in rows or periods. There are 7 periods each period is filled by atomic number. The atomic number is the number of protons each atom has. Almost 120 elements are known. Chemists have learned that 95 percents of your body is made up of some elements on the periodic table. In chemistry any material that can’t be broken down into is known as the elements of science. The order the periodic table is shown shows the trends, like the elements with similar behavior in the same column. This table is known as the periodic table because the rows are called periods. Dmitri was late submitting all his work on the 63 elements. For him to rush things he made a database.Most of the elements on the periodic table are metals. About 75 percent are metals . Metals are usually shiny and most melt at high temperatures. These metals on the periodic table are divided into separate groups, such as basic metals,transition metals,alkali metals,alkaline earth metals,rare earth, lanthanides, and actinides. All of the metals are solid at room temperature except mercury . Mercury is a liquid. Up until medieval times there was only 7 metals known. These elements back then were called the Metals of Antiquity. Most of these metals are good conductors of heat and electricity. Most metals are very hard,malleable or may be beaten into a thin sheet. Many of these metals are ductile or capable of being draw into a wire. They also make a sound like a bell when being struck. These metals tend to bend rather than just break. Metals that are known as metalloids have properties of both metals and nonmetals. Noble metals resist oxidation in moist air. Most precious metals have a meaning or importance. Six non metals occur as
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