element: Discovery of the Elements

Discovery of the Elements

As noted above, some of the elements were discovered in prehistoric times but were not recognized as elements. Arsenic was discovered around 1250 by Albertus Magnus, and phosphorus was discovered about 1674 by Hennig Brand, an alchemist, who prepared it by distilling human urine. Only 12 elements were known before 1700, and only about twice that many by 1800, but by 1900 over 80 elements had been identified. In 1919 Ernest Rutherford found that hydrogen was given off when nitrogen was bombarded with alpha particles. This first transmutation encouraged further study of nuclear reactions, and eventually led to the discovery in 1937 of technetium, the first synthetic element. Neptunium (atomic number 93) was the first transuranium element to be synthesized (1940). Its discovery prompted the search that has led to the ongoing synthesis of additional transuranium elements.

Sections in this article:

Introduction
Discovery of the Elements
Evolution of Modern Concepts
Greek Concept of the Elements
The Elements through the Ages
Official Symbols and Names for the Elements
Properties of the Elements
Atomic Mass and Atomic Weight
Isotopes
Atomic Number and Mass Number
The Atom
Bibliography

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