Deleng sumberé Kadmium

{{Elementbox_header | number=48 | symbol=Cd | name=cadmium | left=[[silver]] | right=[[indium]] | above=[[zinc|Zn]] | below=[[mercury (element)|Hg]] | color1=#ffc0c0 | color2=black }}
{{Elementbox_series | [[transition metal]]s }}
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{{Elementbox_appearance_img | Cd,48| silvery gray metallic }}
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{{Elementbox_density_gpcm3nrt | 8.65 }}
{{Elementbox_densityliq_gpcm3mp | 7.996 }}
{{Elementbox_meltingpoint | k=594.22 | c=321.07 | f=609.93 }}
{{Elementbox_boilingpoint | k=1040 | c=767 | f=1413 }}
{{Elementbox_heatfusion_kjpmol | 6.21 }}
{{Elementbox_heatvaporiz_kjpmol | 99.87 }}
{{Elementbox_heatcapacity_jpmolkat25 | 26.020 }}
{{Elementbox_vaporpressure_katpa | 530 | 583 | 654 | 745 | 867 | 1040 | comment= }}
{{Elementbox_section_atomicprop | color1=#ffc0c0 | color2=black }}
{{Elementbox_crystalstruct | hexagonal }}
{{Elementbox_oxistates | 2<br />(mildly [[base (chemistry)|basic]] oxide) }}
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{{Elementbox_ionizationenergies3 | 867.8 | 1631.4 | 3616 }}
{{Elementbox_atomicradius_pm | [[1 E-10 m|155]] }}
{{Elementbox_atomicradiuscalc_pm | [[1 E-10 m|161]] }}
{{Elementbox_covalentradius_pm | [[1 E-10 m|148]] }}
{{Elementbox_vanderwaalsrad_pm | [[1 E-10 m|158]] }}
{{Elementbox_section_miscellaneous | color1=#ffc0c0 | color2=black }}
{{Elementbox_magnetic | no data }}
{{Elementbox_eresist_ohmm | (22&nbsp;°C) 72.7 n}}
{{Elementbox_thermalcond_wpmkat300k | 96.6 }}
{{Elementbox_thermalexpansion_umpmkat25 | 30.8 }}
{{Elementbox_speedofsound_rodmpsat20 | 2310 }}
{{Elementbox_youngsmodulus_gpa | 50 }}
{{Elementbox_shearmodulus_gpa | 19 }}
{{Elementbox_bulkmodulus_gpa | 42 }}
{{Elementbox_poissonratio | 0.30 }}
{{Elementbox_mohshardness | 2.0 }}
{{Elementbox_brinellhardness_mpa | 203 }}
{{Elementbox_cas_number | 7440-43-9 }}
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{{Elementbox_isotopes_decay | mn=106 | sym=Cd
 | na=1.25% | hl=[[1 E19 s|&gt;9.5×10<sup>17</sup> y]]
 | dm=[[double electron capture|εε2ν]] | de=- | pn=106 | ps=[[palladium|Pd]] }}
{{Elementbox_isotopes_decay | mn=107 | sym=Cd
 | na=[[synthetic radioisotope|syn]] | hl=[[1 E5 s|6.5 h]]
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{{Elementbox_isotopes_decay | mn=108 | sym=Cd
 | na=0.89% | hl=[[1 E19 s|&gt;6.7×10<sup>17</sup> y]]
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{{Elementbox_isotopes_decay | mn=109 | sym=Cd
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{{Elementbox_isotopes_stable | mn=110 | sym=Cd | na=12.49% | n=62 }}
{{Elementbox_isotopes_stable | mn=111 | sym=Cd | na=12.8% | n=63 }}
{{Elementbox_isotopes_stable | mn=112 | sym=Cd | na=24.13% | n=64 }}
{{Elementbox_isotopes_decay | mn=113 | sym=Cd
 | na=12.22% | hl=[[1 E19 s|7.7×10<sup>15</sup> y]]
 | dm=[[beta decay|β<sup>-</sup>]] | de=0.316 | pn=113 | ps=[[indium|In]] }}
{{Elementbox_isotopes_decay2 | mn=113[[nuclear isomer|m]] | sym=Cd
 | na=[[synthetic radioisotope|syn]] | hl=[[1 E8 s|14.1 y]]
 | dm1=[[beta decay|β<sup>-</sup>]] | de1=0.580 | pn1=113 | ps1=[[indium|In]]
 | dm2=[[isomeric transition|IT]] | de2=0.264 | pn2=113 | ps2=Cd }}
{{Elementbox_isotopes_decay | mn=114 | sym=Cd
 | na=28.73% | hl=[[1 E19 s|&gt;9.3×10<sup>17</sup> y]]
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{{Elementbox_isotopes_decay | mn=115 | sym=Cd
 | na=[[synthetic radioisotope|syn]] | hl=[[1 E5 s|53.46 h]]
 | dm=[[beta decay|β<sup>-</sup>]] | de=1.446 | pn=115 | ps=[[indium|In]] }}
{{Elementbox_isotopes_decay | mn=116 | dm=[[double beta decay|ββ2ν]] | de=- | sym=Cd | na=7.49% | hl=[[1 E19 s|2.9×10<sup>19</sup> y]] | pn=116 | ps=[[tin|Sn]] }}
{{Elementbox_isotopes_end}}
{{Elementbox_footer | color1=#ffc0c0 | color2=black }}

'''Cadmium''' ({{pronEng|ˈkædmiəm}}) iku [[unsur kimia]] kanthi simbul '''Cd''' lan [[nomer atom]] 48. 
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A relatively abundant (price 3.55 USD/lb as of 2-15-08), soft, bluish-white, [[transition metal]], cadmium is known to cause [[cancer]] and occurs with [[zinc]] ores. Cadmium is used largely in batteries and [[pigment]]s, for example in [[plastic]] products.

==Extraction==
Cadmium is a common impurity in [[zinc]], and it is most often isolated during the production of zinc. Zinc [[sulfide]] ores are roasted in the presence of [[oxygen]], converting the zinc sulfide to the [[oxide]]. Zinc metal is produced either by [[smelting]] the oxide with [[carbon]] or by [[electrolysis]] in [[sulfuric acid]]. Cadmium is isolated from the zinc metal by [[vacuum distillation]] if the zinc is smelted, or cadmium sulfate is [[precipitate]]d out of the electrolysis solution.<ref>[http://www.webelements.com/webelements/elements/text/Cd/key.html Cadmium] at WebElements.com</ref>

== Notable characteristics ==
Cadmium is a soft, [[malleable]], [[ductile]], toxic, bluish-white [[bivalent]] [[metal]]. It is similar in many respects to [[zinc]] but reacts to form more complex compounds.

The most common [[oxidation state]] of cadmium is +2, though rare examples of +1 can be found.

One particular isotope of cadmium, <sup>113</sup>Cd, absorbs neutrons with very high probability if they have an energy below the ''cadmium cutoff'' and transmits them readily otherwise. The cadmium cutoff is about 0.5 eV <ref>{{cite book |last=Knoll |first=G.F. |title=Radiation Detection and Measurement, 3rd edition |publisher=Wiley |date=1999 |id=ISBN 978-0-471-07338-3}} p505</ref>. Neutrons with energy below the cutoff are deemed slow neutrons, distinguishing them from intermediate and fast neutrons.

[[Image:Cadmium_cutoff.png|thumb|The cadmium-113 total cross section clearly showing the cadmium cutoff.]]

== Applications ==
About three-quarters of cadmium is used in [[Battery (electricity)|batteries]] (especially [[nickel-cadmium battery|Ni-Cd]] batteries), and most of the remaining quarter is used mainly for [[Cadmium pigments|pigments]], coatings and plating, and as stabilizers for [[plastic]]s. Other uses include:
*In some of the lowest-melting [[alloy]]s
*In bearing alloys, due to a low [[coefficient of friction]] and very good fatigue resistance
*In [[electroplating]] (6% cadmium)
*In many kinds of [[solder]]
*As a barrier to control [[nuclear fission]]
*In black and white [[television]] phosphors and in the blue and green phosphors for color television picture tubes
*In paint pigments: Cadmium forms various [[salt]]s, with [[cadmium sulfide]] being the most common. This sulfide is used as a [[Cadmium pigments|yellow pigment]]. [[Cadmium selenide]] can be used as red pigment, commonly called ''cadmium red''. To painters that work with the pigment, cadmium yellows, oranges, and reds are the most potent colours to use. In fact, during production, these colours are significantly toned down before they are ground with oils and binders, or blended into watercolours, gouaches, acrylics, and other paint and pigment formulations. These pigments are toxic, and it is recommended to use a barrier cream on the hands to prevent absorption through the skin when working with them. There is no such thing as cadmium blue, green, or violet. 
*In some [[semiconductor]]s such as cadmium sulfide, cadmium selenide, and [[cadmium telluride]], which can be used for [[light]] detection or [[solar cell]]s. [[HgCdTe]] is sensitive to [[infrared]].
*In [[Polyvinyl chloride|PVC]] as stabilizers.
*In molecular biology, used to block voltage-dependent calcium channels from fluxing calcium ions.

:''See also [[:Category:Cadmium compounds]].''

== History ==
Cadmium ([[Latin]] ''cadmia'', [[Greek language|Greek]] ''καδμεία'' meaning "[[calamine]]", a Cadmium-bearing mixture of minerals, which was named after the Greek mythological character, Κάδμος ([[Cadmus]])) was [[discovery of the chemical elements|discovered]] in  [[Germany]] in [[1817]] by [[Friedrich Strohmeyer]]. Strohmeyer found the new element within an impurity in [[zinc carbonate]] (calamine), and, for 100 years, Germany remained the only important producer of the metal. The metal was named after the Latin word for calamine, since the metal was found in this zinc compound. Strohmeyer noted that some impure samples of calamine changed color when heated but pure calamine did not.

Even though cadmium and its compounds are highly toxic, the [[British Pharmaceutical Codex]] from 1907 states that [[cadmium iodide]] was used as a [[medicine]] to treat "enlarged joints, scrofulous glands, and chilblains".

In [[1927]], the [[Bureau International des Poids et Mesures|International Conference on Weights and Measures]] redefined the [[metre|meter]] in terms of a red cadmium spectral line (1m = 1,553,164.13 wavelengths). This definition has since been changed (see [[krypton]]).

== Occurrence ==
[[Image:CadmiumMetalUSGOV.jpg|thumb|left|Cadmium metal]]
[[Image:2005cadmium.PNG|thumb|left|Cadmium output in 2005]]
[[Image:Cadmium - world production trend.svg|thumb|World production trend]]
In 2001, China was the top producer of cadmium with almost one-sixth world share closely followed by South Korea and Japan, reports the [[British Geological Survey]].

Cadmium-containing ores are rare and, when found, occur in small quantities. [[Greenockite]] (Cd[[sulfur|S]]), the only cadmium [[mineral]] of importance, is nearly always associated with [[sphalerite]] ([[zinc|Zn]]S). As a consequence, cadmium is produced mainly as a byproduct from mining, smelting, and refining [[sulfide]] ores of zinc, and, to a lesser degree, [[lead]] and [[copper]]. Small amounts of cadmium, about 10% of consumption, are produced from secondary sources, mainly from dust generated by recycling [[iron]] and [[steel]] scrap.  Production in the [[United States]] began in [[1907]], but it was not until after [[World War I]] that cadmium came into wide use.

:''See also [[:Category:Cadmium minerals]].''

==Biological role==
A role of cadmium in biology has been recently discovered. A cadmium-dependent [[carbonic anhydrase]] has been found in marine [[diatom]]s. Cadmium does the same job as zinc in other anhydrases, but the diatoms live in environments with very low zinc concentrations, thus biology has taken cadmium rather than zinc, and made it work. The discovery was made using X-ray absorption fluoresence spectroscopy (XAFS), and cadmium was characterised by noting the energy of the X-rays that were absorbed.

[[Image:HeCd laser.jpg|thumb|left|150px|Image of the violet light from a [[helium]] cadmium metal vapor [[laser]]. The highly [[monochromatic]] color arises from the 441.563 nm transition [[spectral line|line]] of cadmium.]]

==Isotopes of cadmium==
{{main|isotopes of cadmium}}
Naturally occurring cadmium is composed of 8 [[isotope]]s. For two of them, natural [[radioactivity]] was observed, and three others are predicted to be [[radioactive]] but their decays were never observed, due to extremely long [[half-life]] times. The two natural radioactive isotopes are <sup>113</sup>Cd ([[beta decay]], [[half-life]] is 7.7 × 10<sup>15</sup> years) and <sup>116</sup>Cd (two-neutrino [[double beta decay]], [[half-life]] is 2.9 × 10<sup>19</sup> years). The other three are <sup>106</sup>Cd, <sup>108</sup>Cd ([[double electron capture]]), and <sup>114</sup>Cd ([[double beta decay]]); only lower limits on their [[half-life]] times have been set. At least three isotopes - <sup>110</sup>Cd, <sup>111</sup>Cd, and <sup>112</sup>Cd - are absolutely stable. Among the isotopes absent in the natural cadmium, the most long-lived are <sup>109</sup>Cd with a half-life of 462.6 days, and <sup>115</sup>Cd with a half-life of 53.46 hours. All of the remaining [[radioactive]] isotopes have half-lives that are less than 2.5 hours, and the majority of these have half-lives that are less than 5 minutes. This element also has 8 known [[meta state]]s, with the most stable being <sup>113m</sup>Cd (t<sub>½</sub> 14.1 years), <sup>115m</sup>Cd (t<sub>½</sub> 44.6 days), and <sup>117m</sup>Cd (t<sub>½</sub> 3.36 hours).

The known isotopes of cadmium range in [[atomic mass]] from 94.950 [[atomic mass unit|u]] (<sup>95</sup>Cd) to 131.946 u (<sup>132</sup>Cd). The primary [[decay mode]] before the second-most-abundant stable isotope, <sup>112</sup>Cd, is [[electron capture]], and the primary modes after are [[beta emission]] and [[electron capture]]. The primary [[decay product]] before <sup>112</sup>Cd is element 47 ([[silver]]), and the primary product after is element 49 ([[indium]]).<br style="clear:left;"/>

== Toxicity ==
{{main|Cadmium poisoning}}

Cadmium is an [[occupational hazard]] associated with industrial processes such as metal plating and the production of nickel-cadmium batteries, pigments, plastics, and other synthetics.  The primary route of exposure in industrial settings is inhalation.  Inhalation of cadmium-containing fumes can result initially in [[metal fume fever]] but may progress to chemical [[pneumonitis]], [[pulmonary edema]], and death.<ref>[http://www.ijmt.net/ijmt/4_5/4_5_41.html] Principles and Methods of Toxicology (fourth edition). A. Wallace Hayes. Taylor and Francis Publishing Inc.; Philadelphia, 2001.</ref>

Cadmium is also a potential environmental hazard.  Human exposures to environmental cadmium are primarily the result of the burning of fossil fuels and municipal wastes.<ref>[http://www.epa.gov/ttn/atw/hlthef/cadmium.html EPA summary on cadmium]</ref>  However, there have been notable instances of toxicity as the result of long-term exposure to cadmium in contaminated food and water.  In the decades following [[World War II]], Japanese mining operations contaminated the [[Jinzu River]] with cadmium and traces of other toxic metals.  As a consequence, cadmium accumulated in the rice crops growing along the riverbanks downstream of the mines.  The local agricultural communities consuming the contaminated rice developed [[Itai-itai]] disease and renal abnormalities, including [[proteinuria]] and [[glucosuria]].<ref>[http://www.springerlink.com/content/n0773057mw738u05/] Environmental cadmium exposure, adverse effects, and preventative measures in Japan. Nogowa et al. Biometals. 2004 Oct; 17(5):581-7.</ref> Cadmium is one of six substances banned by the European Union's [[ROHS|Restriction on Hazardous Substances]] (RoHS) directive, which bans carcinogens in computers.

Cadmium and several cadmium-containing compounds are known [[carcinogen]]s and can induce many types of [[cancer]].<ref>[http://ntp.niehs.nih.gov/index.cfm?objectid=32BA9724-F1F6-975E-7FCE50709CB4C932 11th Report on Carcinogens] provided by the National Toxicology Program</ref>

Current research has found that cadmium toxicity may be carried into the body by [[zinc]] binding proteins; in particular, proteins that contain [[zinc finger]] protein structures. Zinc and cadmium are in the same group on the periodic table, contain the same common oxidation state (+2), and when ionized are almost the same size. Due to these similarities, cadmium can replace zinc in many biological systems, in particular, systems that contain softer ligands such as sulfur. Cadmium can bind up to ten times more strongly than zinc in certain biological systems, and is notoriously difficult to remove. In addition, cadmium can replace [[magnesium]] and [[calcium]] in certain biological systems, although these replacements are rare.

Tobacco smoking is the most important single source of cadmium exposure in the general population. It has been estimated that about 10% of the cadmium content of a cigarette is inhaled through smoking. The absorption of cadmium from the lungs is much more effective than that from the gut, and as much as 50% of the cadmium inhaled via cigarette smoke may be absorbed.

On average, smokers have 4-5 times higher blood cadmium concentrations and 2-3 times higher kidney cadmium concentrations than non-smokers. Despite the high cadmium content in cigarette smoke, there seems to be little exposure to cadmium from [[passive smoking]]. No significant effect on blood cadmium concentrations could be detected in children exposed to environmental tobacco smoke.

==Precautions==
While working with cadmium, it is important to do so under a [[fume hood]] or with the use of an appropriate [[respirator]] to protect against dangerous fumes.<ref>[http://www.osha.gov/SLTC/cadmium/solutions.html OSHA Solutions for workplace cadmium exposure]</ref> [[Solder]], for example, which may contain cadmium, should be handled with care.
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== Rujukan ==
<references/>

== Pranala njaba ==
{{wiktionarypar|cadmium}}
{{Commons|Cadmium}}
{{Wikisource1911Enc|Cadmium}}
* [http://www-cie.iarc.fr/htdocs/monographs/vol58/mono58-2.htm IARC Monograph "Cadmium and Cadmium Compounds"] {{Webarchive|url=https://web.archive.org/web/20051015082333/http://www-cie.iarc.fr/htdocs/monographs/vol58/mono58-2.htm |date=2005-10-15 }}
* [http://www.npi.gov.au/database/substance-info/profiles/17.html National Pollutant Inventory - Cadmium and compounds]
* [http://www.webelements.com/webelements/elements/text/Cd/index.html WebElements.com – Cadmium]
* [http://periodic.lanl.gov/elements/48.html Los Alamos National Laboratory – Cadmium] {{Webarchive|url=https://web.archive.org/web/20090228191622/http://periodic.lanl.gov/elements/48.html |date=2009-02-28 }}
* [http://publicdocs.mnr.gov.on.ca/View.asp?Document_ID=10690&Attachment_ID=25585] {{Webarchive|url=https://web.archive.org/web/20090609233824/http://publicdocs.mnr.gov.on.ca/View.asp?Document_ID=10690&Attachment_ID=25585 |date=2009-06-09 }} Warning Moose and Deer Liver
* [http://www.cdc.gov/niosh/topics/Cadmium National Institute for Occupational Safety and Health - Cadmium Page]
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[[Kategori:Cadmium]]

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