View source for Periodic Table

{{header}}
{{spelling}}

The [[Periodic Table|Periodic Table of elements]] is a listing of known elements organized by their [[atomic number]]. The Periodic Table was changed over time and the order has changed to have their atomic numbers in order but also by listing them by their properties.<ref> Los Alamos National Laboratory's Chemistry Division Dec 11, 2003 periodic table of elements -retrieve date 2-5-09 </ref> 

=== Periods ===
Each row is a '''period''' of elements in which chemical properties repeat.  Periods tells us many things such as electronegativity and ionization energy and much more. Electronegativity increases as you move left to right from a period. Atomic radius decreases as you move left to right in a period. Ionization energy increases as you move left to right. Elements that are in the same period have the same number electron shells  Atomic number also increases as you move left to right in a period in the periodic table. 

== Periodic Law ==
<div style="margin-left:25px"><small><i>Main article</i>: [[Periodic Law]]</small></div>
{{:Periodic Law}}

== Periodic Trends ==
<div style="margin-left:25px"><small><i>Main article</i>: [[Periodic Trends]]</small></div>
{{:Periodic Trends}}

=== Groups ===
The columns are '''groups''' or families. The elements in each group have similar properties because they have the same amount of valance electrons in the outer orbital giving each of the elements their unique properties. Dimitri Mendeleev was the first to organize the periodic table.<ref> Lackman, Jon 2005 "Elemental" -retrieve date 2-6-09 </ref> 

<br style="clear:both">
{{elements}}

== History ==
<div style="margin-left:25px"><small><i>Main article</i>: [[Periodic Table History |History]]</small></div>
{{:Periodic Table History}}

== Categories of Elements ==
<div style="margin-left:25px"><small><i>Main article</i>: [[Element_categories]]</small></div>
{{:Element_categories}}

== Properties of the Elements ==
In the periodic table there are special elements like the elements with the atomic number of 84 and up that are unstable and so they are radio active and can become a different element and release harmful particles like alpha and beta particles and gamma rays that are even more harmful. No element higher than 92 occur naturally, these elements are produced artificially in nuclear reactions.<ref> David D. Hsu. 1996 chemicool -retrieve date 2-5-09</ref> Another type of elements is the elements in group 18 or 8a that are the noble gases that don't bond to other elements and have the electron configuration that all elements are required to have. The alkali metals all react violently in water.

==Atomic Radius==
The atomic radius increases as you move down and left.

==Ionic Radius== 
The ionic radius increases as you move down and left. Cation are smaller and anions are larger. 

==Metallic Character/Metal Reactivity== 
Metallic character/Metal Reactivity increase as you move down and left. 

==1st Ionization Energy== 
1st ionization energy  increases as you move up and right. 

==Electronegativity== 
Electronegativity increases as you move up and right. 

==Nonmetallic Character/Nonmetal Reaction==
Nonmetallic Character/Nonmetal Reaction increases as you move up and right. 

==Cation and Anions==
Cations are the metals and anions are the nonmetals. 


[[Image:Periodic_Table_of_the_Elements.png|thumb|300px|right|The [[Periodic Table|Periodic Table of Elements]] is a key tool for chemists.]]

== Download ==
[[Image:California_Reference_Sheet_Periodic_Table_of_the_Elements.png|thumb|300px|The '''California Reference Sheet''' provides a copy of the Periodic Table of the Elements during the STAR exam.]]

[http://thechembook.com/images/b/bc/Periodic_Table_Elements.doc Periodic Table of Elements]
<br style="clear:both">
== Further Reading ==
[http://www.uky.edu/Projects/Chemcomics/ The Comic Book Periodic Table of Elements]

http://library.thinkquest.org/C006669/data/Chem/atomic/metals.html

== Reference ==
{{reflist|2}}

{{Footer}}

[[Category:Unit 1]]
[[Category:Standard_1]]