History of periodic table

The early Greeks thought that all material on Earth was constructed of a combination of four basic elements: earth, water, air and fire.

In the pre-Christian era the ancients knew only seven basic metals: gold (Au), silver (Ag), copper (Cu), lead (Pb), tin (Sn), iron (Fe), and mercury (Hg).

Mercury was discovered last, about the 4th century BC. The ancient knew about sulfur (S), but called it brimstone, and carbon in the form of diamonds and charcoal.

In 1669 a group of German chemists isolated phosphorus the first minerals element to be accurately identified. On of the next major development, was due to Jeremias Benjamin Richter, who between 1792 and 1794 published a set of quantities that later became known as equivalent weights.

The periodic table was discovered in 1869 by as many as five or six individuals including Russian chemist Dmitri Mendeleev (1834-1907) at about the same times, following the rationalization of atomic weights at the Karlsruhe conference.

The periodic table of the chemical elements is organized as a matrix of rows of horizontal ‘periods’ that list the elements in their increasing atomic numbers and generally, according to their atomic weights.

The table was revised by British physicist Henry Moseley (1887-1915), who came up with the concept of atomic numbers, numbers based on the number of protons (positively charge particles) in an elemental atom.

The periodic table is a clean, crisp way of characterizing the elements, and if anybody are now or ever were a chemistry, physics or premed student, he can testify first hand to the of memorizing the information it provides.
History of periodic table