Everything about Atomic Number totally explained
In
chemistry and
physics, the
atomic number (also known as the
proton number) is the number of
protons found in the
nucleus of an
atom. It is traditionally represented by the symbol
Z. The atomic number uniquely identifies a
chemical element. In an atom of
neutral charge, atomic number is equal to the number of
electrons.
The atomic number is closely related to the
mass number, which is the total number of protons and
neutrons in the nucleus of an atom.
History
The atomic number originally was used to signify the element's location in the
periodic table.
Dmitri Mendeleev arranged the known elements in increasing order of
atomic weight and grouped by their similar chemical properties. However, placing the elements in strict order of atomic weight resulted in some mismatches.
Iodine and
tellurium, if listed by atomic weight, appeared to be in the wrong order; and would fit better by chemical properties if their places in the table were swapped. Placing them in the order which fit their properties most closely, their number in the table was their atomic number. This number appeared to be related to the mass of the atom but, as the discrepancy showed, reflected some property other than mass.
The anomalies in this sequence were finally explained after research by
Henry Gwyn Jeffreys Moseley in 1913. Moseley discovered a strict relationship between the
x-ray diffraction spectra of elements, and their correct location in the periodic table. This led to the conclusion that the atomic number corresponds to the
electric charge of the nucleus—the charge of the protons. The atomic number is the number of protons that's equal to the number of electrons. The proton charge is positive and the electron charge is negative.
Chemical properties
Each element has a specific set of chemical properties as a consequence of the number of protons in its nucleus. The charge of an atom's nucleus defines its
electron configuration based on principles of
quantum mechanics. The form of each element's
electron shells, particularly the
valence shell, is the primary factor in determining its
chemical bonding behavior.
New elements
The quest for new elements is usually described using atomic number. As of early 2007, elements with atomic numbers through 118 (excluding 117) have been discovered. Synthesis of new elements is accomplished by bombarding target atoms of heavy elements with ions, such that the sum of the atomic numbers of the target and ion elements equals the atomic number of the element being created. In general, the
half-life becomes shorter as atomic number increases, though an "
island of stability" may exist for undiscovered isotopes with certain numbers of protons and neutrons.
Further Information
Get more info on 'Atomic Number'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://atomic_number.totallyexplained.com">Atomic number Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
