The periodic table's name comes from the fact that it arranges the elements into repeating sets, otherwise known as "periods." These periods are defined by the covalence of an element, the number of electrons it has in its outermost shell and by other elemental attributes. This arrangement places elements with similar chemical properties close to one another.Know More
Periods are often defined as recurring sets of behavior. Russian chemist and inventor Dmitri Mendeleev was one of the first scientists to realize the attributes that certain groups of chemical elements had in common. He used this observation and formed one of the earliest versions of the periodic table. Mendeleev then sorted the elements according to these patterns to create the periodic table as it is known today.
Mendeleev's table did not include all of the elements that it does now, as many elements had yet to be discovered at that time. However, his table was able to predict that newly discovered elements would fit certain profiles and he designed the table to accommodate this. For this reason, scientists have been able to regularly update the periodic table by adding new elements alongside substances with similar properties instead of replacing the table with another model altogether.Learn more about Chemistry
The elements that make up Group 13, the boron family, are boron, aluminum, gallium, indium and thallium. All elements have three valence electrons, the electrons in the most outer shell. All elements in the boron family are metals except for boron, which is a metalloid.Full Answer >
When Dmitri Mendeleev created the Periodic Table of the Elements, he decided against arranging them by their atomic numbers based on his correct assumption that those numbers were not totally accurate. When he first began to arrange the 60 known elements in the 1860s, he knew that new elements would eventually be discovered there are now over 100 known elements and that the atomic weights of the elements known at that time had been calculated incorrectly.Full Answer >
The elements in the periodic table are organized by their atomic numbers, their electron configurations and the recurring properties found in them. Elements are arranged in blocks, with elements found in that block all containing consistent properties. For instance, all alkali metals are highly reactive, and all noble gases are inert, meaning they cannot react with other elements under normal conditions.Full Answer >
The periodic table is useful because it identifies and arranges all known elements in an informative manner. Elements are arranged into periods and families. The elements in each family or period may have similar or dissimilar physical and chemical properties.Full Answer >