Difference between revisions of "Calcium"
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| − | + | {{Infobox element | |
| + | <!-- top --> | ||
| + | |image name=Calcium under argon atmosphere.jpg | ||
| + | |image alt= | ||
| + | |image size= | ||
| + | |image name comment=Calcium metal under argon. | ||
| + | |image name 2= | ||
| + | |image alt 2= | ||
| + | |image size 2= | ||
| + | |image name 2 comment= | ||
| + | <!-- General properties --> | ||
| + | |name=Calcium | ||
| + | |symbol=Ca | ||
| + | |pronounce= | ||
| + | |pronounce ref= | ||
| + | |pronounce comment= | ||
| + | |pronounce 2= | ||
| + | |alt name= | ||
| + | |alt names= | ||
| + | |allotropes= | ||
| + | |appearance= | ||
| + | <!-- Periodic table --> | ||
| + | |above= | ||
| + | |below= | ||
| + | |left= | ||
| + | |right= | ||
| + | |number= | ||
| + | |atomic mass= | ||
| + | |atomic mass 2= | ||
| + | |atomic mass ref= | ||
| + | |atomic mass comment= | ||
| + | |series= | ||
| + | |series ref= | ||
| + | |series comment= | ||
| + | |series color= | ||
| + | |group= | ||
| + | |group ref= | ||
| + | |group comment= | ||
| + | |period= | ||
| + | |period ref= | ||
| + | |period comment= | ||
| + | |block= | ||
| + | |block ref= | ||
| + | |block comment= | ||
| + | |electron configuration= | ||
| + | |electron configuration ref= | ||
| + | |electron configuration comment= | ||
| + | |electrons per shell= | ||
| + | |electrons per shell ref= | ||
| + | |electrons per shell comment= | ||
| + | <!-- Physical properties --> | ||
| + | |physical properties comment= | ||
| + | |color=Silvery-gray | ||
| + | |phase= | ||
| + | |phase ref= | ||
| + | |phase comment= | ||
| + | |melting point K= | ||
| + | |melting point C= | ||
| + | |melting point F= | ||
| + | |melting point ref= | ||
| + | |melting point comment= | ||
| + | |boiling point K= | ||
| + | |boiling point C= | ||
| + | |boiling point F= | ||
| + | |boiling point ref= | ||
| + | |boiling point comment= | ||
| + | |sublimation point K= | ||
| + | |sublimation point C= | ||
| + | |sublimation point F= | ||
| + | |sublimation point ref= | ||
| + | |sublimation point comment= | ||
| + | |density gplstp= | ||
| + | |density gplstp ref= | ||
| + | |density gplstp comment= | ||
| + | |density gpcm3nrt= | ||
| + | |density gpcm3nrt ref= | ||
| + | |density gpcm3nrt comment= | ||
| + | |density gpcm3nrt 2= | ||
| + | |density gpcm3nrt 2 ref= | ||
| + | |density gpcm3nrt 2 comment= | ||
| + | |density gpcm3nrt 3= | ||
| + | |density gpcm3nrt 3 ref= | ||
| + | |density gpcm3nrt 3 comment= | ||
| + | |density gpcm3mp= | ||
| + | |density gpcm3mp ref= | ||
| + | |density gpcm3mp comment= | ||
| + | |density gpcm3bp= | ||
| + | |density gpcm3bp ref= | ||
| + | |density gpcm3bp comment= | ||
| + | |molar volume= | ||
| + | |molar volume unit = | ||
| + | |molar volume ref= | ||
| + | |molar volume comment= | ||
| + | |triple point K= | ||
| + | |triple point kPa= | ||
| + | |triple point ref= | ||
| + | |triple point comment= | ||
| + | |triple point K 2= | ||
| + | |triple point kPa 2= | ||
| + | |triple point 2 ref= | ||
| + | |triple point 2 comment= | ||
| + | |critical point K= | ||
| + | |critical point MPa= | ||
| + | |critical point ref= | ||
| + | |critical point comment= | ||
| + | |heat fusion= | ||
| + | |heat fusion ref= | ||
| + | |heat fusion comment= | ||
| + | |heat fusion 2= | ||
| + | |heat fusion 2 ref= | ||
| + | |heat fusion 2 comment= | ||
| + | |heat vaporization= | ||
| + | |heat vaporization ref= | ||
| + | |heat vaporization comment= | ||
| + | |heat capacity= | ||
| + | |heat capacity ref= | ||
| + | |heat capacity comment= | ||
| + | |heat capacity 2= | ||
| + | |heat capacity 2 ref= | ||
| + | |heat capacity 2 comment= | ||
| + | |vapor pressure 1= | ||
| + | |vapor pressure 10= | ||
| + | |vapor pressure 100= | ||
| + | |vapor pressure 1 k= | ||
| + | |vapor pressure 10 k= | ||
| + | |vapor pressure 100 k= | ||
| + | |vapor pressure ref= | ||
| + | |vapor pressure comment= | ||
| + | |vapor pressure 1 2= | ||
| + | |vapor pressure 10 2= | ||
| + | |vapor pressure 100 2= | ||
| + | |vapor pressure 1 k 2= | ||
| + | |vapor pressure 10 k 2= | ||
| + | |vapor pressure 100 k 2= | ||
| + | |vapor pressure 2 ref= | ||
| + | |vapor pressure 2 comment= | ||
| + | <!-- Atomic properties --> | ||
| + | |atomic properties comment= | ||
| + | |oxidation states= | ||
| + | |oxidation states ref= | ||
| + | |oxidation states comment= | ||
| + | |electronegativity= | ||
| + | |electronegativity ref= | ||
| + | |electronegativity comment= | ||
| + | |ionization energy 1= | ||
| + | |ionization energy 1 ref= | ||
| + | |ionization energy 1 comment= | ||
| + | |ionization energy 2= | ||
| + | |ionization energy 2 ref= | ||
| + | |ionization energy 2 comment= | ||
| + | |ionization energy 3= | ||
| + | |ionization energy 3 ref= | ||
| + | |ionization energy 3 comment= | ||
| + | |number of ionization energies= | ||
| + | |ionization energy ref= | ||
| + | |ionization energy comment= | ||
| + | |atomic radius= | ||
| + | |atomic radius ref= | ||
| + | |atomic radius comment= | ||
| + | |atomic radius calculated= | ||
| + | |atomic radius calculated ref= | ||
| + | |atomic radius calculated comment= | ||
| + | |covalent radius= | ||
| + | |covalent radius ref= | ||
| + | |covalent radius comment= | ||
| + | |Van der Waals radius= | ||
| + | |Van der Waals radius ref= | ||
| + | |Van der Waals radius comment= | ||
| + | <!-- Miscellanea --> | ||
| + | |crystal structure= | ||
| + | |crystal structure prefix= | ||
| + | |crystal structure ref= | ||
| + | |crystal structure comment= | ||
| + | |crystal structure 2= | ||
| + | |crystal structure 2 prefix= | ||
| + | |crystal structure 2 ref= | ||
| + | |crystal structure 2 comment= | ||
| + | |speed of sound= | ||
| + | |speed of sound ref= | ||
| + | |speed of sound comment= | ||
| + | |speed of sound rod at 20= | ||
| + | |speed of sound rod at 20 ref= | ||
| + | |speed of sound rod at 20 comment= | ||
| + | |speed of sound rod at r.t.= | ||
| + | |speed of sound rod at r.t. ref= | ||
| + | |speed of sound rod at r.t. comment= | ||
| + | |thermal expansion= | ||
| + | |thermal expansion ref= | ||
| + | |thermal expansion comment= | ||
| + | |thermal expansion at 25= | ||
| + | |thermal expansion at 25 ref= | ||
| + | |thermal expansion at 25 comment= | ||
| + | |thermal conductivity= | ||
| + | |thermal conductivity ref= | ||
| + | |thermal conductivity comment= | ||
| + | |thermal conductivity 2= | ||
| + | |thermal conductivity 2 ref= | ||
| + | |thermal conductivity 2 comment= | ||
| + | |thermal diffusivity= | ||
| + | |thermal diffusivity ref= | ||
| + | |thermal diffusivity comment= | ||
| + | |electrical resistivity= | ||
| + | |electrical resistivity unit prefix= | ||
| + | |electrical resistivity ref= | ||
| + | |electrical resistivity comment= | ||
| + | |electrical resistivity at 0= | ||
| + | |electrical resistivity at 0 ref= | ||
| + | |electrical resistivity at 0 comment= | ||
| + | |electrical resistivity at 20= | ||
| + | |electrical resistivity at 20 ref= | ||
| + | |electrical resistivity at 20 comment= | ||
| + | |band gap= | ||
| + | |band gap ref= | ||
| + | |band gap comment= | ||
| + | |Curie point K= | ||
| + | |Curie point ref= | ||
| + | |Curie point comment= | ||
| + | |magnetic ordering= | ||
| + | |magnetic ordering ref= | ||
| + | |magnetic ordering comment= | ||
| + | |tensile strength= | ||
| + | |tensile strength ref= | ||
| + | |tensile strength comment= | ||
| + | |Young's modulus= | ||
| + | |Young's modulus ref= | ||
| + | |Young's modulus comment= | ||
| + | |Shear modulus= | ||
| + | |Shear modulus ref= | ||
| + | |Shear modulus comment= | ||
| + | |Bulk modulus= | ||
| + | |Bulk modulus ref= | ||
| + | |Bulk modulus comment= | ||
| + | |Poisson ratio= | ||
| + | |Poisson ratio ref= | ||
| + | |Poisson ratio comment= | ||
| + | |Mohs hardness= | ||
| + | |Mohs hardness ref= | ||
| + | |Mohs hardness comment= | ||
| + | |Mohs hardness 2= | ||
| + | |Mohs hardness 2 ref= | ||
| + | |Mohs hardness 2 comment= | ||
| + | |Vickers hardness= | ||
| + | |Vickers hardness ref= | ||
| + | |Vickers hardness comment= | ||
| + | |Brinell hardness= | ||
| + | |Brinell hardness ref= | ||
| + | |Brinell hardness comment= | ||
| + | |CAS number= | ||
| + | |CAS number ref= | ||
| + | |CAS number comment= | ||
| + | <!-- History --> | ||
| + | |naming= | ||
| + | |predicted by= | ||
| + | |prediction date ref= | ||
| + | |prediction date= | ||
| + | |discovered by= | ||
| + | |discovery date ref= | ||
| + | |discovery date= | ||
| + | |first isolation by= | ||
| + | |first isolation date ref= | ||
| + | |first isolation date= | ||
| + | |discovery and first isolation by= | ||
| + | |named by= | ||
| + | |named date ref= | ||
| + | |named date= | ||
| + | |history comment label= | ||
| + | |history comment= | ||
| + | <!-- Isotopes --> | ||
| + | |isotopes= | ||
| + | |isotopes comment= | ||
| + | |engvar= | ||
| + | }} | ||
'''Calcium''' is a chemical element with symbol '''Ca''' and atomic number 20. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust. | '''Calcium''' is a chemical element with symbol '''Ca''' and atomic number 20. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust. | ||
Revision as of 17:10, 16 April 2017
 Calcium metal under argon. | |||||
| General properties | |||||
|---|---|---|---|---|---|
| Name, symbol | Calcium, Ca | ||||
| Calcium in the periodic table | |||||
| |||||
| Standard atomic weight (Ar) | |||||
| Group, block | , -block | ||||
| Period | period | ||||
| Electron configuration | |||||
| Physical properties | |||||
| Silvery-gray | |||||
| Atomic properties | |||||
Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust.
Contents
Properties
Chemical
Calcium is reactive towards air but is often kept in a sealed container as opposed to under oil as its oxidation is not excessively rapid. As pellets or turnings, the metal can be difficult to ignite, more so even than magnesium turnings, but when lit the metal burns in air with a brilliant red light, producing calcium oxide.
Calcium reacts with the usually inert nitrogen, forming calcium nitride. If a container of calcium is left open in a glove box full of nitrogen, the metal will quickly be ruined.
Calcium produces hydrogen on contact with water, at a noticeably slower rater than all the alkali metals when in the same from but powder calcium is much more common than any alkali metal powders, and the increased surface area of the metal produces a rapid reaction. Part of the reason for the slowness of the calcium–water reaction is a result of the metal being partly protected by insoluble white calcium hydroxide. In acids where the calcium salt is soluble, the metal reacts vigorously.
At very high temperatures (usually in an arc furnace) the metal reacts with carbon to produce the useful calcium carbide.
Physical
Calcium is a soft for a metal (though harder than lead, it can be cut with a knife with difficulty). It is a silvery metallic element with a density of 1.55 g/cm3. Calcium has the lowest density of the alkaline earth metals; magnesium (specific gravity 1.74) and beryllium (1.84) are denser though lighter in atomic mass. From strontium onward, the alkali earth metals become denser with increasing atomic mass.
Availability
Calcium can be bought at Gallium Source.
As a reducing agent, it suffers some of the stigma and restrictions sodium does because it can be used in the manufacture of illicit drugs. In Australia, purchasing calcium metal requires an EUD.
Preparation
Preparing calcium metal is not easy or economical for the amateur chemist. It can be extracted by electrolysis from a fused salt like calcium chloride. Once produced, it rapidly forms a gray-white oxide and nitride coating when exposed to air.
Projects
- Producing calcium carbide
- Make calcium nitride
- Extracting lanthanides
Handling
Safety
Compared with other metals, the calcium ion and most calcium compounds have low toxicity. This is not surprising given the very high natural abundance of calcium compounds in the environment and in organisms. Acute calcium poisoning is rare, and difficult to achieve unless calcium compounds are administered intravenously.
Calcium metal is hazardous because of it reacts violently with water and acids. Calcium metal is found in some drain cleaners, where it functions to generate heat and calcium hydroxide that saponifies the fats and liquefies the proteins (e.g., hair) that block drains. When swallowed calcium metal has the same effect on the mouth, esophagus and stomach, and can be fatal.
Storage
Large pieces of calcium metal can be stored in dry air without any severe degradation, as noted by many chemists. Turnings and calcium powder is much more reactive. Like all air-sensitive materials, calcium must be stored in sealed containers or glass ampoules, in an inert atmosphere (such as argon). It can also be stored in mineral oil.
Disposal
Calcium metal can be neutralized by slowly dissolving it in water or simply leaving it in wet air, which turns it into calcium oxide, hydroxide and finally carbonate (or sulfate/nitrate, depending on the quality of air).
As calcium compounds are abundant in the environment and pose no toxicity, no special treatment is required to dispose of them. However it is advised to avoid dumping the poorly soluble ones down the drain as they might build up and clog the pipes.
