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An element is a
substance composed of atoms with a unique number of protons in each
nucleus. There are 92 naturally occurring and 15 manmade elements
Following is a list of elements in
periodic table.
A chemical element is a pure
chemical substance consisting of one type of atom distinguished by its
atomic number, which is the number of protons in its nucleus.[1] Common
examples of elements are iron, copper, silver, gold, hydrogen, carbon,
nitrogen, and oxygen. In total, 118 elements have been observed as of
March 2010, of which 94 occur naturally on Earth. 80 elements have
stable isotopes, namely all elements with atomic numbers 1 to 82, except
elements 43 and 61 (technetium and promethium). Elements with atomic
numbers 83 or higher (bismuth and above) are inherently unstable, and
undergo radioactive decay. The elements from atomic number 83 to 94 have
no stable nuclei, but are nevertheless found in nature, either surviving
as remnants of the primordial stellar nucleosynthesis that produced the
elements in the solar system, or else produced as short-lived
daughter-isotopes through the natural decay of uranium and thorium.[2]
All chemical matter consists of these elements. New elements of higher
atomic number are discovered from time to time, as products of
artificial nuclear reactions.
List of
Elements |
