{| align="right" style="margin:0 0 1em 1em;"
! [[Periodic table group|Group]]
! 1
|-
! [[Periodic table period|Period]]
|
|-
! [[Period 1 element|1]]
| {{element cell| 1|Hydrogen|H| |Gas|Nonmetals|Primordial}}
|-
! [[Period 2 element|2]]
| {{element cell| 3|Lithium|Li| |Solid|Alkali metals|Primordial}}
|-
! [[Period 3 element|3]]
| {{element cell|11|Sodium|Na| |Solid|Alkali metals|Primordial}}
|-
! [[Period 4 element|4]]
| {{element cell|19|Potassium|K| |Solid|Alkali metals|Primordial}}
|-
! [[Period 5 element|5]]
| {{element cell|37|Rubidium|Rb| |Solid|Alkali metals|Primordial}}
|-
! [[Period 6 element|6]]
| {{element cell|55|Cesium|Cs| |Solid|Alkali metals|Primordial}}
|-
! [[Period 7 element|7]]
| {{element cell|87|Francium|Fr| |Solid|Alkali metals|Natural radio}}
|}

The '''alkaline metals''' are a [[chemical series|series]] of [[chemical element|elements]] comprising [[Periodic table group|Group 1]] ([[International Union of Pure and Applied Chemistry|IUPAC]] style) of the [[periodic table]]: [[Lithium]] ('''Li'''),[[sodium]] ('''Na'''), [[potassium]] ('''K'''), [[rubidium]] ('''Rb'''), [[cesium]] ('''Cs'''), and [[francium]] ('''Fr'''). (Note that [[hydrogen]], although nominally also a member of Group 1, very rarely exhibits behavior comparable to the alkali metals). The alkali metals provide one of the best examples of group trends in properties in the periodic table, with well characterized homologous behavior down the group.

The alkali metals are all highly reactive and are rarely found in elemental form in nature. As a result, in the laboratory they are stored under [[mineral oil]]. They also tarnish easily and have low melting points and densities. Potassium and rubidium possess a weak radioactive characteristic (harmless) due to the presence of long duration radioactive isotopes.

The alkali metals are silver-colored (cesium has a golden tinge), soft, low-[[density]] [[metal]]s, which react readily with [[halogen]]s to form [[ionic salt]]s, and with [[water (molecule)|water]] to form strongly [[alkali]]ne [[Base (chemistry)|(basic)]] [[hydroxide]]s. These elements all have one [[electron]] in their outermost shell, so the energetically preferred state of achieving a filled [[electron shell]] is to lose one electron to form a singly [[electric charge|charged]] positive [[ion]], or cation.

[[Hydrogen]], with a solitary electron, is usually placed at the top of Group 1 of the periodic table, but it is not considered an alkali metal; rather it exists naturally as a diatomic [[gas]]. Removal of its single electron requires considerably more energy than removal of the outer electron for the alkali metals. As in the [[halogen]]s, only one additional electron is required to fill in the outermost shell of the hydrogen atom, so hydrogen can in some circumstances behave like a halogen, forming the negative [[hydride]] ion. [[Binary compound]]s of hydride with the alkali metals and some [[transition metal]]s have been prepared. Under extremely high [[pressure]], such as is found at the core of [[Jupiter]], hydrogen does become metallic and behaves like an alkali metal; see [[metallic hydrogen]]. it cause a nuclear reaction with air or water

Alkali metals have the lowest ionization potentials in their respective periods, as removing the single electron from the outermost shell gives them the stable inert gas configuration. But their second ionization potentials are very high, as removing an electron from a species having a noble gas configuration is very difficult.

[[Image:Alkalimetalle.jpg|thumb|350px|Series of alkali metals, stored in mineral oil (note "natrium" is sodium.)]]
Alkali metals are famous for their vigorous reactions with water, and these reactions become increasingly violent as one moves down the group. The reaction with water is as follows:

Alkali metal + water → Alkali metal hydroxide + hydrogen gas

With [[potassium]] as an example:

:2K (s) + 2H₂O (l) → 2KOH (aq) + H₂ (g)

===Reaction in ammonia===
Alkali metals dissolve in liquid [[ammonia]] to give blue solutions that are [[paramagnetic]].
As the solution approaches saturation, it becomes deep purple, then metallic.

:[[Potassium|K]] + [[Ammonia|NH₃]] → K⁺ + [[Electron|e^-]]

Because the solution contains free electrons, it occupies more space than the sum of the volumes of the metal and ammonia. The presence of free electrons also makes these solutions very good [[reducing agent]]s and good [[conductor_(electricity)|electrical conductors]]. Since they are easier to handle than the metals themselves they are sometimes used as substitutes.

The solution is not stable over long periods, and the dissolved alkali metal will react to form the corresponding [[amide]]. This reaction, when accelerated with a catalyst (usually [[iron(III) nitrate]]), is used for the production of [[sodium amide]]:

:2 [[Sodium|Na]] + 2 [[Ammonia|NH₃]] → 2 [[Sodium_amide|NaNH₂]] + [[Hydrogen|H₂]]

The amide can be extracted, or it can be converted to [[sodium azide]] by bubbling [[nitrous oxide]] through the ammonia solution:

:2 [[Sodium_amide|NaNH₂]] + [[Nitrous_oxide|N₂O]] → [[Sodium_azide|NaN₃]] + [[Sodium_hydroxide|NaOH]] + [[Ammonia|NH₃]]

==Trends==

The alkali metals show a number of trends when moving down the group - for instance, decreasing electronegativity, increasing reactivity, and decreasing melting and boiling point. Density generally increases, with the notable exception of potassium being less dense than sodium, and the possible exception of francium being less dense than caesium.

<table border=0 cellpadding=2 cellspacing=0 width="100%">
<tr>
<td bgcolor="#CCCCFF">'''Alkali metal'''</td>
<td bgcolor="#CCCCFF" align="center">'''Standard Atomic Weight ([[unified atomic mass unit|u]])'''</td>
<td bgcolor="#CCCCFF" align="center">'''Melting Point ([[kelvin|K]])'''</td>
<td bgcolor="#CCCCFF" align="center">'''Boiling Point ([[kelvin|K]])'''</td>
<td bgcolor="#CCCCFF" align="center">'''Density ([[gram|g]]·[[centimeter|cm]]⁻³)'''</td>
<td bgcolor="#CCCCFF" align="center">'''Electronegativity ([[Pauling scale|Pauling]])'''</td>
</tr>

<tr>
<td>Lithium</td>
<td align="center">6.941</td>
<td align="center">453.69</td>
<td align="center">1615</td>
<td align="center">0.534</td>
<td align="center">0.98</td>
</tr>
<tr>
<td bgcolor="#EEEEEE">Sodium</td>
<td bgcolor="#EEEEEE" align="center">22.990</td>
<td bgcolor="#EEEEEE" align="center">370.87</td>
<td bgcolor="#EEEEEE" align="center">1156</td>
<td bgcolor="#EEEEEE" align="center">0.968</td>
<td bgcolor="#EEEEEE" align="center">0.93</td>
</tr>
<tr>
<td>Potassium</td>
<td align="center">39.098</td>
<td align="center">336.53</td>
<td align="center">1032</td>
<td align="center">0.89</td>
<td align="center">0.82</td>
</tr>
<tr>
<td bgcolor="#EEEEEE">Rubidium</td>
<td bgcolor="#EEEEEE" align="center">85.468</td>
<td bgcolor="#EEEEEE" align="center">312.46</td>
<td bgcolor="#EEEEEE" align="center">961</td>
<td bgcolor="#EEEEEE" align="center">1.532</td>
<td bgcolor="#EEEEEE" align="center">0.82</td>
</tr>
<tr>
<td>Caesium</td>
<td align="center">132.905</td>
<td align="center">301.59</td>
<td align="center">944</td>
<td align="center">1.93</td>
<td align="center">0.79</td>
</tr>
<tr>
<td bgcolor="#EEEEEE">Francium</td>
<td bgcolor="#EEEEEE" align="center">(223)</td>
<td bgcolor="#EEEEEE" align="center">? 295</td>
<td bgcolor="#EEEEEE" align="center">? 950</td>
<td bgcolor="#EEEEEE" align="center">? 1.87</td>
<td bgcolor="#EEEEEE" align="center">0.7</td>
</tr>
</table>

==Biological occurrences==

* The metal lithium is not essential for any biological functions, but was found to exist in extremely tiny quantities in [[umbilical cord]] blood. This was found during a study by taking blood samples of newborns from both the umbilical cord and the mother at the time of birth, and subjecting the samples to a number of tests. They found that there was 7 times the amount of lithium in blood than previously believed. (Krachler and Rossipal 488) While it is considered a non-essential trace element (an element needed in extremely tiny amounts for proper growth), lithium also has medicinal uses. A double-blind, placebo-controlled, two-week long study conducted by a group of doctors on severely depressed patients proved that lithium is a key component in the treatment of severe depression. (Joffe, Levitt, and Sokolov, 791) It has also been proven to play a role in the treatment of other mental disorders. (Bildik et al. 277) One recorded instance was the case of a girl who developed a condition known as [[Neuroleptic malignant syndrome]], who was given an antipsychotic drug (a tranquilizing drug that induces a state of relative calm). She quickly developed the symptoms of NMS, and was quickly hospitalized. There, doctors began treating her for the disorder, and in the final stage of her treatment, lithium was administered to her to help stabilize her mental functions. Weeks later, she was released and was in good physical health, but retained her previous diagnosis of Bipolar Disorder (a mental disorder that encompasses periods of mania and depression interspersed by periods of normal behavior). (Bildik et al. 278)

* Sodium and potassium are very common alkali metals. These elements are essential for the existence of all known life. They are found in the cytoplasm (organic fluid, mainly water) of all living cells, and they are critical to everyday cell operation and regulation. (Chang and Tsong 587) Also, a common sodium salt, sodium chloride (table salt), has been identified many times as a contributor to [[hypertension]] in humans. (Sharp 727) A double-blind, two-month study was conducted on a group of elderly adults by modestly cutting their salt intake, to find if cutting salt intake would lower blood pressure. Some in the group were given half the salt that others were given for the duration of the study. The findings indicated that those who were given only half the amount of salt experienced a drop in blood pressure of up to 7.2 mm Hg (millimeters Mercury). (Cappacio and Markandu 850)

* Rubidium is not required for any known biological functions, but is known to be an unnecessary and toxic trace-element in humans. (Krachler and Rossipal 488) A recent study conducted on rubidium levels in freshwater ecosystems from Lake Erie and two Arctic lakes indicate that this element biomagnifies (the concentration grows as you move higher in the food chain) in marine food chains. This was found by collecting samples of fish, birds and plankton, and conducting tests on them. They found that the predatory animals (the small-mouth bass, for example) had higher rubidium concentrations than animals commonly considered to be prey. (Campbell et al. 1163)

* Caesium (also spelled cesium) is not typically found in any biological systems. However, cesium salt (cesium chloride) is a popular medicinal supplement taken to counteract the effects of damaged or diseased cells on the body. (Ackerman et al. 1011) Furthermore, this supplement has been shown to be toxic to human physiology, and has caused very serious side effects in people, and potentially can be deadly if not taken carefully. (Ackerman et al. 1011)

* Francium is an extremely rare element, and its chemical and physical properties have not been characterized to the same extent as the other alkali metals. It is known to have the same chemistry as cesium and is primarily an exotic curiosity in the world of physics. At any one moment in time, less than one ounce of francium is believed to exist on Earth, and its most stable [[isotope]] has a half life of a little less than 23 minutes.("Physics update" 9) This makes working with the element dangerous and difficult and radiochemistry techniques must be used to characterize its chemical properties. It has not been found to exist in any biological systems, and while there is no direct evidence of this, it is assumed to be true due to the rarity and instability of the element.

==Reference material==

* Campbell, Linda M., Aaron T. Fisk, Xianowa Wang, Gunter Kock, and Derek C. Muir. "Evidence for Biomagnification of Rubidium in Freshwater and Marine Food Webs." Canadian Journal of Fisheries and Aquatic Sciences 62 (2005): 1161-1167. Academic Search Elite. EBSCO. McIntyre Library, Eau Claire. 1 May 2007 <http://web.ebscohost.com/ehost/detail?vid=4&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* Chang, Cheng-Hung, and Tian Y. Tsong. Stochastic Resonance of Na, K-Ion Pumps on the Red Cell Membrane. Noise and Fluctuations: 18th International Conference on Noise and Fluctuations, 2005, American Institute of Physics. 30 Apr. 2007 <http://web.ebscohost.com/ehost/detail?vid=11&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* Sokolov, Stephen T., Russell T. Joffe, and Anthony J. Levitt. "Lithium and Triiodothyronine Augmentation of Antidepressants." Canadian Journal of Psychiatry 51 (2006): 791-793. Academic Search Elite. EBSCO. McIntyre Library, Eau Claire. 29 Apr. 2007 <http://web.ebscohost.com/ehost/detail?vid=7&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* Bauer, Brent A., Robert Houlihan, Michael J. Ackerman, Katya Johnson, and Himeshkumar Vyas. "Acquired Long QT Syndrome Secondary to Cesium Chloride Supplement." The Journal of Alternative and Complementary Medicine 12 (2006): 1011-1014. Academic Search Elite. EBSCO. McIntyre Library, Eau Claire. 3 May 2007 <http://web.ebscohost.com/ehost/detail?vid=14&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* Erermis, Serpil, Muge Tamar, Hatice Karasoy, Tezan Bildik, Eyup S. Ercan, and Ahmet Gockay. Zuclopenthixol-Induced Neuroleptic Malignant Syndrome in an Adolescent Girl. Clinical Toxicology. Informa Healthcare, 2007. 277-280. 6 May 2007 <http://web.ebscohost.com/ehost/detail?vid=23&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* Sharp, Kelly. "Hypertension: Just the Facts." Ed. Joyce A. Marrs. Clinical Journal of Oncology Nursing 10 (2006): 727-729. Academic Search Elite. EBSCO. McIntyre Library, Eau Claire. 8 May 2007 <http://web.ebscohost.com/ehost/detail?vid=26&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* Cappacio, F P., and N D. Markandu. "Double-Blind Randomised Trial of Modest Salt Restriction in Older People." Lancet 350 (1997): 850-854. Academic Search Elite. EBSCO. McIntyre Library, Eau Claire. 6 Mar. 2007 <http://web.ebscohost.com/ehost/detail?vid=29&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* Krachler, M, and E Rossipal. "Trace Elements Transfer From Mother to the Newborn - Investigations on Triplets of Colostrum, Maternal and Umbilical Sera." European Journal of Clinical Nutrition 53 (1999): 486-494. EBSCO. McIntyre Library, Eau Claire. 9 May 2007 <http://web.ebscohost.com/ehost/detail?vid=47&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* "Physics Update." Physics Today June 1996: 9. Academic Search Elite. EBSCO. McIntyre Library, Eau Claire. 9 May 2007 <http://web.ebscohost.com/ehost/detail?vid=56&hid=108&sid=0795c290-e438-449b-a713-f035a2e12aa4%40sessionmgr109>.

* "Visual Elements: Group 1 - The Alkali Metals." <u>Visual Elements.</u> Royal Society of Chemistry. <http://www.chemsoc.org/Viselements/pages/data/intro_groupi_data.html>.

==See also==
*[[Lithium]]
*[[Sodium]]
*[[Potassium]]
*[[Rubidium]]
*[[Caesium]]
*[[Francium]]

==External links==
*[http://www.scienceaid.co.uk/chemistry/periodictable/alkalimetals.html Science aid:Alkali metals] A simple look at alkali metals
*[http://www.wpbschoolhouse.btinternet.co.uk/page03/Alkali_Metals.htm Doc Brown, Alkali metals]
*[http://www.chemguide.co.uk/inorganic/group1/properties.html Atomic and Physical Properties of the Group 1 Elements] An in-depth look at alkali metals

{|style="text-align: center;" border="1" cellpadding="2"
|+ '''Explanation of above periodic table slice:'''
| bgcolor="{{element color/Alkali metals}}" | Alkali metals
| Atomic numbers in <font color="{{element color/Solid}}">{{element color/Solid}}</font> are solids
| style="border:{{element frame/Primordial}};" | Solid borders indicate [[primordial element]]s (older than the [[Earth]])
| style="border:{{element frame/Natural radio}};" | Dashed borders indicate natural [[radioactive decay|radioactive element]]s with no isotopes older than the Earth
|}

{{PeriodicTablesFooter}}
{{alkalimetals}}
<!--Category-->

[[Category:Alkali metals]]
[[Category:Periodic table]]

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[[ar:فلز قلوي]]
[[ast:Alcalín]]
[[bn:ক্ষার ধাতু]]
[[bs:Alkalni metali]]
[[bg:Група 1А на периодичната система]]
[[ca:Metall alcalí]]
[[cs:Alkalický kov]]
[[cy:Metel alcalïaidd]]
[[da:Alkalimetal]]
[[de:Alkalimetalle]]
[[et:Leelismetallid]]
[[el:Αλκάλια]]
[[es:Alcalino]]
[[eo:Alkala metalo]]
[[eu:Metal alkalino]]
[[fa:فلز قلیایی]]
[[fr:Métal alcalin]]
[[gl:Alcalino]]
[[ko:알칼리 금속]]
[[hr:Alkalijski metali]]
[[id:Logam alkali]]
[[is:Alkalímálmur]]
[[it:Metalli alcalini]]
[[he:מתכת אלקלית]]
[[sw:Metali alikali]]
[[la:Metallum alkalicum]]
[[lv:Sārmu metāli]]
[[lt:Šarminiai metalai]]
[[lmo:Metàj alcalítt]]
[[hu:Alkálifém]]
[[mk:Алкален метал]]
[[ms:Logam alkali]]
[[nl:Alkalimetaal]]
[[ja:第1族元素]]
[[no:Alkalimetall]]
[[nn:Alkalimetall]]
[[nds:Alkalimetall]]
[[pl:Metale alkaliczne]]
[[pt:Alcalino-metálicos]]
[[ksh:Alkalimetall]]
[[ro:Metal alcalin]]
[[qu:Alkali q'illay]]
[[ru:Щелочные металлы]]
[[simple:Alkali metal]]
[[sk:Alkalické kovy]]
[[sl:Alkalijska kovina]]
[[sr:Алкални метали]]
[[sh:Alkalni metali]]
[[fi:Alkalimetalli]]
[[sv:Alkalimetall]]
[[ta:கார மாழைகள்]]
[[te:క్షార లోహము]]
[[th:โลหะแอลคาไล]]
[[vi:Kim loại kiềm]]
[[tr:Alkali metal]]
[[uk:Лужні метали]]
[[zh-yue:鹼金屬]]
[[zh:碱金属]]