991,951
edits
Changes
mLine 1:
Line 1: + − {{Elementbox − |number=55 − |symbol=Cs − |name=caesium − |pronounce={{IPAc-en|ˈ|s|iː|z|i|ə|m}} {{respell|SEE|zee-əm}} − |left=[[xenon]] − |right=[[barium]] − |above=[[rubidium|Rb]] − |below=[[francium|Fr]] − |series=alkali metal − |series comment= − |group=1 − |period=6 − |block=s − |appearance=silvery gold − |image name=Cesium.jpg − |image size= − |image alt=Some silvery-gold metal, with a liquid-like texture and lustre, sealed in a glass ampoule − |atomic mass= 132.90545196 − |atomic mass 2=6 − |electron configuration=[[[xenon|Xe]]] 6s<sup>1</sup> − |electrons per shell= 2, 8, 18, 18, 8, 1 − |density gpcm3nrt=1.93 − |density gpcm3mp=1.843 − |melting point K=301.7 − |melting point C=28.5 − |melting point F=83.3 − |melting point pressure= − |boiling point K=944 − |boiling point C=671 − |boiling point F=1240 − |boiling point pressure= − |triple point K= − |triple point kPa= − |triple point K 2= − |triple point kPa 2= − |critical point K=1938 − |critical point MPa=9.4 − |heat fusion=2.09 − |heat fusion 2= − |heat fusion pressure= − |heat vaporization=63.9 − |heat vaporization pressure= − |heat capacity=32.210 − |heat capacity pressure= − |vapor pressure 1=418 − |vapor pressure 10=469 − |vapor pressure 100=534 − |vapor pressure 1 k=623 − |vapor pressure 10 k=750 − |vapor pressure 100 k=940 − |vapor pressure comment= − |crystal structure=body-centered cubic − |oxidation states='''1''', −1<br />(strongly [[base (chemistry)|basic]] oxide) − |oxidation states comment= − |electronegativity=0.79 − |number of ionization energies=3 − |1st ionization energy=375.7 − |2nd ionization energy=2234.3 − |3rd ionization energy=3400 − |atomic radius=265 − |atomic radius calculated= − |covalent radius=244±11 − |Van der Waals radius=[[1 E-10 m|343]] − |magnetic ordering= [[paramagnetic]]<ref name=magnet>{{cite book|url=http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf|format=PDF|chapter=Magnetic susceptibility of the elements and inorganic compounds|title=Handbook of chemistry and physics|edition=87th|publisher=CRC press|accessdate=2010-09-26|isbn=0-8493-0487-3}}</ref> − |electrical resistivity= − |electrical resistivity at 0= − |electrical resistivity at 20=205 n − |thermal conductivity=35.9 − |thermal conductivity 2= − |thermal diffusivity= − |thermal expansion= − |thermal expansion at 25=97 − |speed of sound= − |speed of sound rod at 20= − |speed of sound rod at r.t.= − |Tensile strength= − |Young's modulus=1.7 − |Shear modulus= − |Bulk modulus=1.6 − |Poisson ratio= − |Mohs hardness=0.2 − |Vickers hardness= − |Brinell hardness=0.14 − |CAS number=7440-46-2 − }}<noinclude> − Caesium is an [[alkali]] [[metal]]. Its [[melt]]ing point is low (28 °C). It is extremely [[Reaction|react]]ive. Because of its high reactivity, it is a [[danger]]ous chemical. It may set itself on fire (ignite) in air. It [[Explosion|explode]]s on contact with water. It reacts more violently than the other [[alkali metal]]s with water. Because of this, caesium is stored in [[mineral]] [[oil]].<ref name=USGS>William C. Butterman ''et al'' 2004. {{cite web|url = http://pubs.usgs.gov/of/2004/1432/2004-1432.pdf|format = PDF|publisher = United States Geological Survey|accessdate = 2009-12-27|title = Mineral Commodity Profile: Cesium}}</ref> − + + + Line 98:
Line 14: + + + + − − {{Link FA|de}} − {{Link FA|en}} − {{Link GA|ja}}
KS update 1.1
{{infobox caesium}}
'''Caesium''' (or '''cesium''') is the [[chemical element]] with the [[atomic number]] 55 on the [[periodic table]]. Its symbol is '''Cs'''.
'''Caesium''' (or '''cesium''') is the [[chemical element]] with the [[atomic number]] 55 on the [[periodic table]]. Its symbol is '''Cs'''.
Caesium is a rare element. Since there is little caesium on the [[Earth]], it is rather expensive. The human body does not need caesium. In large amounts, it is mildly poisonous because it is close to [[potassium]], which the body does need.
Caesium is an [[alkali]] [[metal]]. Its [[melt]]ing point is low (28 °C). It is extremely [[Reaction|react]]ive. Because of its high reactivity, it is a [[danger]]ous chemical. It may set itself on fire (ignite) in air. It [[Explosion|explode]]s on contact with water. It reacts more violently than the other [[alkali metal]]s with water. Because of this, caesium is stored in [[mineral oil]].<ref name=USGS>William C. Butterman ''et al'' 2004. {{cite web|url = http://pubs.usgs.gov/of/2004/1432/2004-1432.pdf|format = PDF|publisher = United States Geological Survey|accessdate = 2009-12-27|title = Mineral Commodity Profile: Cesium}}</ref>
Caesium is a rare element. Since there is little caesium on the [[Earth]], it is rather expensive. The human body does not need caesium. In large amounts, its [[chemical compound]]<nowiki/>s are mildly poisonous because it is close to [[potassium]], which the body does need.
== History ==
== History ==
Caesium forms [[Chemical compound|compounds]] with many other [[chemical element]]s. Caesium formate is used in oil drilling because of its high [[density]].
Caesium forms [[Chemical compound|compounds]] with many other [[chemical element]]s. Caesium formate is used in oil drilling because of its high [[density]].
== Reactivity ==
Caesium is extremely reactive in air and water. Caesium rapidly oxidizes in air and can spontaneously combust<ref>{{Cite web|url=https://www.compoundchem.com/2019/08/06/iypt055-caesium/|title=IYPT 2019 Elements 055: Caesium: Atomic clocks and explosive reactions|last=Interest|first=Compound|date=2019-08-06|website=Compound Interest|language=en-GB|access-date=2019-11-13}}</ref> (randomly catch on fire) at any moment. For this reason, it [http://www.chemistryexplained.com/elements/A-C/Cesium.html must be stored in] [[kerosene]] or a [[Oil|mineral oil,]] like other group one elements ([[Lithium|Lithium,]] [[Sodium|Natrium]], [[Rubidium]], and [[Francium]].) In water, Caesium violently reacts to make Caesium Hydroxide (2CsOH).<ref>{{Cite web|url=https://www.webelements.com/caesium/chemistry.html|title=WebElements Periodic Table » Caesium » reactions of elements|website=www.webelements.com|access-date=2019-11-13}}</ref> The Caesium sinks for about one second, then explodes. The explosion is over 50 times the size of the size of the element dropped in the water, and the explosion is enough to break a common Pyrex [[Beaker]], [[Flask]], or [[Test tube|Test Tube]]. You can find a video of the reaction [https://www.youtube.com/watch?v=5Vd5pqjbWJU here.]
==References==
==References==
{{reflist}}
{{reflist}}
{{Periodic Table}}
{{Periodic Table}}
[[Category:Alkali metals]]
[[Category:Alkali metals]]
[[Category:Chemical elements]]
[[Category:Chemical elements]]