The Uses of the Periodic Table

The periodic table of elements was developed by Dmitri Mendeleev, a Russian chemist, and presented by him in 1869. At the time, it contained 65 elements arranged in grid. The elements were, and still are, classified according to certain properties and their atomic weights. For example, the elements to the left of the table have higher atomic weights than those on the right. As of today, the periodic table contains 112 elements.

Basic Facts

The periodic table is the most important reference in chemistry. Elements on it are arranged left to right in the order of increasing atomic number (which usually corresponds to increasing atomic mass). The rows of the table are called periods. The more electrons there are in an element, the lower the period in which it is found. Furthermore, elements with similar chemical properties to other elements are arranged in the same column of the periodic table.

Function

Mendeleev developed the table such that it allowed for elements that were yet to be discovered. For example, he noted gaps where elements that were not yet known should be placed, based on their chemical properties and atomic weights. Places are still open today, and the table continues to be filled with new elements. For example, five radioactive elements are in the process of being approved.

Use

Chemists use the periodic table to organize and study elements found in the world. The table gives them basic information regarding each known element, in blocks. Each block of the periodic table consists of specific information pertaining to an element. There is the element's atomic symbol (such as B for boron). There is its atomic number above the symbol (in boron's case, 5) and its atomic mass below the symbol (in boron's case, 10.81). The atomic symbol is one or two letters that represent the element. That atomic number is the number of protons in one atom of the element, which in turn characterizes the element's chemical behavior. An element's atomic mass is the total mass of protons, neutrons and electrons in a single atom of the element.

Features

An important feature of the periodic table is how it relates to different elements' electron configurations. For example, the table's Group 18 consists of the noble gases and is made up of the column at the farthest right of the table. Noble gases are known for their lack of reactivity and thus have a very stable electron configuration. This configuration consists of a full outer shell of electrons. On the other hand, elements in the table's Group 1 are called alkali metals and are on the farthest left side of the table. They are known to be highly reactive because they are able to lose and gain electrons easily.

Other Features

There is a progression from metals to nonmetals across the table's periods. Elements in Groups 3 through 12 contain transition metals, which are similar to one another. Their similarities include variable valency, the ability to catalyze and the ability to produce color compounds.