The Periodic Table
The periodic table was discovered in 1869 by a Russian scientist named Dmitri Mendeleev. Many attempts were made in the early 1800s to organize the arrangement of elements. Mendeleev published the table based on the elements increasing atomic mass. When he published the table it was missing pieces and he claimed that they were yet to be found. How right was he? He predicted the table based on the organization of the elements and believed that each element had chemical and physical properties alike in the same column.
The periodic table’s elements are arranged in groups or families. Mendeleev grouped the elements by similar properties. The most common groups are: alkali metals, alkaline earth metals, transition metals, halogens, and noble gases. Each element has an atomic number, atomic symbol and atomic mass. The atomic number is the number of protons and electrons in an atom. It is also what basically defines the element. The atomic symbol represents the element by one or two letters, such as, the letter “O” would represent oxygen. The atomic mass is the mass of the atom, which is the number of protons plus the number of neutrons in an atom. The vertical columns of the periodic table are how the elements are classified and the horizontal rows represent the trends.
There are a total of 117 known elements in the periodic table. The table is used worldwide by students, scientists, and researchers all the same. It has proved to be a steady reference chart that can provide information to those who use it almost instantly. The table has established structure throughout the years and not only helps simplify chemistry, but it is able to predict new elements.