The periodic table classifies chemical elements by their similarities and properties. Each square in the periodic table shows an element's atomic number, its symbol, its name and its atomic weight, which is the number of... More »

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 i... More »

The periodic table was invented by chemist Dmitri Mendeleev to organize and compare elements and understand their relations with each other. Mendeleev created the periodic table between 1868 and 1870 while writing his bo... More »

Periodic law, also known as Mendeleev's law, is the concept that the chemical and physical properties of elements are based on an element's atomic weight when arranged by increasing periodic atomic number. Periodic law w... More »

The MCAT periodic table is the periodic table made available to test takers of the Medical College Admission Test (MCAT). It includes the same information as typical periodic tables, listing the atomic numbers and atomic... More » Science Chemistry Atoms & Molecules

The periodic table arranges the known elements in order of increasing atomic number, which typically coincides with increasing atomic mass. Different rows on the table are known as periods. The period number assigned to ... More »

Many elements on the periodic table have names derived from Latin, including aluminum, calcium, cesium, chlorine, fluorine, gallium, iridium, radium, rubidium and scandium. Other element names are derived from languages ... More »