Dmitri Mendeleev and the Periodic Table of Elements
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The Periodic Table of Elements

The Organization of the Periodic Table of Elements

The Periodic Table of Elements is organized by the elements' atomic mass. It is also organized into groups and periods. The periods are the  horizontal rows. They change from left to right in a predictable pattern. The vertical rows are called groups, or families. There are 18 groups."Because the pattern of properties of elements repeats in each new period, the elements in each group have similar characteristics. "

On the periodic table, there are 111 known and confirmed elements. 86 of those are metals. out of those metals, 21 are not found in nature, and one is a liquid. The rest are solid. There are 17 nonmetals on the periodic table. 11 of them are gases, 1 is a liquid, and 5 are solid. There are 8 metalloids, and all are solid. Also on the period table are 6 elements whose discoveries have not officially been confirmed. 5 of them, their properties have not yet been established, but one of them is definitely a metal.

Each element has its own square. Each square includes the atomic number, chemical symbol, name, and atomic mass. The atomic number tells you how many protons are in the atom's nucleus. Since there always an equal number of protons and electrons in an atom, the atomic number also tells you how many electrons are in the atom. Directly below the atomic number is the chemical symbol. Generally, the chemical symbol contains one or two letters and is the abbreviation for the element's name in English. However, some elements (especially those known in ancient times) have chemical symbols that are abbreviations of their Latin name. The name directly below the chemical symbol is the English name for the element. The last number is the atomic mass. "The atomic mass is an average because most elements consist of a mixture of isotopes. For example, iron is a mixture of four isotopes. About 92 percent of iron atoms are iron -56 (having 30 nuetrons). The rest are a mixture of iron-54, iron-57, and iron-58. The average atomic mass of iron is determined from the combined percentages of all its isotopes." If you take the atomic mass, round it, and then subtract the atomic number from it, you will get the number of nuetrons in the atom.
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