* Isoforms I, III and VIII are also stimulated by Ca < sup > 2 +</ sup >/ calmodulin.

* Isoforms V and VI are inhibited by Ca < sup > 2 +</ sup > in a calmodulin-independent manner.

In neurons, calcium-sensitive adenylate cyclases are located next to calcium ion channels for faster reaction to Ca < sup > 2 +</ sup > influx ; they are suspected of playing an important role in learning processes.

Calcium ion ( Ca < sup >++</ sup >) antagonists ( Calcium channel blockers ) are used in the treatment of chronic stable angina.

The inorganic composition of bone ( bone mineral ) is formed from carbonated hydroxyapatite ( Ca < sub > 10 </ sub >( PO < sub > 4 </ sub >)< sub > 6 </ sub >( OH )< sub > 2 </ sub >) with lower crystallinity.

Calcium is essential for living organisms, in particular in cell physiology, where movement of the calcium ion Ca < sup > 2 +</ sup > into and out of the cytoplasm functions as a signal for many cellular processes.

Calcium salts are colorless from any contribution of the calcium, and ionic solutions of calcium ( Ca < sup > 2 +</ sup >) are colorless as well.

Calcium has four stable isotopes (< sup > 40 </ sup > Ca, < sup > 42 </ sup > Ca, < sup > 43 </ sup > Ca and < sup > 44 </ sup > Ca ), plus two more isotopes (< sup > 46 </ sup > Ca and < sup > 48 </ sup > Ca ) that have such long half-lives that for all practical purposes they also can be considered stable.

This forms another material known as slaked lime ( Ca ( OH )< sub > 2 </ sub >), which is an inexpensive base material used throughout the chemical industry.

This Ca < sup > 2 +</ sup > eventually is transported to the ocean where it reacts with dissolved CO < sub > 2 </ sub > to form limestone.

The result is that each Ca < sup > 2 +</ sup > ion released by chemical weathering ultimately removes one CO < sub > 2 </ sub > molecule from the surficial system ( atmosphere, ocean, soils and living organisms ), storing it in carbonate rocks where it is likely to stay for hundreds of millions of years.

As the weathering of limestone ( CaCO < sub > 3 </ sub >) liberates equimolar amounts of Ca < sup > 2 +</ sup > and CO < sub > 2 </ sub >, it has no net effect on the CO < sub > 2 </ sub > content of the atmosphere and ocean.

The weathering of silicate rocks like granite, on the other hand, is a net CO < sub > 2 </ sub > sink because it produces abundant Ca < sup > 2 +</ sup > but very little CO < sub > 2 </ sub >.

* Calcium hydroxide solution ( Ca ( OH )< sub > 2 </ sub >) ( also known as limewater ) is used to detect the presence of carbon dioxide by being bubbled through a solution.

Prominent among these are the H-line at 3968. 5 Å and the K line at 3933. 7 Å of singly ionized calcium, or Ca II.

In the early 1980s, the concentration of ionic species ( in g / kg ) of Dead Sea surface water was Cl < sup >−</ sup > ( 181. 4 ), Br < sup >−</ sup > ( 4. 2 ), SO < sub > 4 </ sub >< sup > 2 −</ sup > ( 0. 4 ), HCO < sub > 3 </ sub >< sup >−</ sup > ( 0. 2 ), Ca < sup > 2 +</ sup > ( 14. 1 ), Na < sup >+</ sup > ( 32. 5 ), K < sup >+</ sup > ( 6. 2 ) and Mg < sup > 2 +</ sup > ( 35. 2 ).

in period 4: K, Ca, Sc, Ti, V, Cr, Fe, Ni have 1, 2, 3, 4, 5, 6, 8, 10 valence electrons respectively.

The most common phosphate is the apatite group ; common species within this group are fluroapatite ( Ca < sub > 5 </ sub >( PO < sub > 4 </ sub >)< sub > 3 </ sub > F ), chlorapatite ( Ca < sub > 5 </ sub >( PO < sub > 4 </ sub >)< sub > 3 </ sub > Cl ) and hydroxylapatite ( Ca < sub > 5 </ sub >( PO < sub > 4 </ sub >)< sub > 3 </ sub >( OH )).

*** Hibschite: Ca < sub > 3 </ sub > Al < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3-x </ sub >( OH )< sub > 4x </ sub > ( where x is between 0. 2 and 1. 5 )

*** Katoite: Ca < sub > 3 </ sub > Al < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3-x </ sub >( OH )< sub > 4x </ sub > ( where x is greater than 1. 5 )

The general formula can be given as ( Ca, Na )< sub > 2 – 3 </ sub >( Mg, Fe, Al )< sub > 5 </ sub >( Al, Si )< sub > 8 </ sub > O < sub > 22 </ sub >( OH, F )< sub > 2 </ sub >.

* Tremolite Ca < sub > 2 </ sub > Mg < sub > 5 </ sub > Si < sub > 8 </ sub > O < sub > 22 </ sub >( OH )< sub > 2 </ sub >

* Actinolite Ca < sub > 2 </ sub >( Mg, Fe )< sub > 5 </ sub > Si < sub > 8 </ sub > O < sub > 22 </ sub >( OH )< sub > 2 </ sub >

* Hornblende Ca < sub > 2 </ sub >( Mg, Fe, Al )< sub > 5 </ sub >( Al, Si )< sub > 8 </ sub > O < sub > 22 </ sub >( OH )< sub > 2 </ sub >

* Richterite Na < sub > 2 </ sub > Ca ( Mg, Fe )< sub > 5 </ sub > Si < sub > 8 </ sub > O < sub > 22 </ sub >( OH )< sub > 2 </ sub >

Ca < sup > 2 +</ sup > activates the selective cation channel transient receptor potential melastatin 5 ( TrpM5 ) that leads to membrane depolarization and the consequent release of ATP and secretion of neurotransmitters including serotonin.

Representative abrasives include particles of aluminum hydroxide ( Al ( OH )< sub > 3 </ sub >), calcium carbonate ( CaCO < sub > 3 </ sub >), various calcium hydrogen phosphates, various silicas and zeolites, and hydroxyapatite ( Ca < sub > 5 </ sub >( PO < sub > 4 </ sub >)< sub > 3 </ sub > OH ).

Around 5 am 2nd Corps under Mac-Mahon ( two infantry divisions and a cavalry brigade under La Motterouge, Decaen and Gaudin ) encountered Hungarian units posted near Ca ’ Morino ( Medole ).

* Calcium aluminoferrite, Ca < sub > 2 </ sub >( Al, Fe )< sub > 2 </ sub > O < sub > 5 </ sub >, a mineral found in cements

* Calcium arsenate ( Ca < sub > 3 </ sub >( AsO < sub > 4 </ sub >)< sub > 2 </ sub >) is used in insecticides.

* Calcium phosphate ( Ca < sub > 3 </ sub >( PO < sub > 4 </ sub >)< sub > 2 </ sub >) is used as a supplement for animal feed, fertilizer, in commercial production for dough and yeast products, in the manufacture of glass, and in dental products.

Calcium sulfoaluminate cements are made from clinkers that include ye ' elimite ( Ca < sub > 4 </ sub >( AlO < sub > 2 </ sub >)< sub > 6 </ sub > SO < sub > 4 </ sub > or C < sub > 4 </ sub > A < sub > 3 </ sub > in Cement chemist's notation ) as a primary phase.

The best studied example is Ca < sub > 0. 4 </ sub > K < sub > 0. 6 </ sub >( NO < sub > 3 </ sub >)< sub > 1. 4 </ sub >.

Epidotes are built around the structure < sup > 10 -</ sup > structure ; for example, the mineral species epidote has calcium, aluminium, and ferric iron to charge balance: Ca < sub > 2 </ sub > Al < sub > 2 </ sub >( Fe < sup > 3 +</ sup >, Al )( SiO < sub > 4 </ sub >)( Si < sub > 2 </ sub > O < sub > 7 </ sub >) O ( OH ).

The ugrandite garnets have Ca < sup > 2 +</ sup > in the X position: uvarovite ( Ca < sub > 3 </ sub > Cr < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >), grossular ( Ca < sub > 3 </ sub > Al < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >) and andradite ( Ca < sub > 3 </ sub > Fe < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >).

In the Nitrophosphate process or Odda Process ( invented in 1927 ), phosphate rock with up to a 20 % phosphorus ( P ) content is dissolved with nitric acid ( HNO < sub > 3 </ sub >) to produce a mixture of phosphoric acid ( H < sub > 3 </ sub > PO < sub > 4 </ sub >) and calcium nitrate ( Ca ( NO < sub > 3 </ sub >)< sub > 2 </ sub >).

The formula of the admixture of the four most common endmembers is written as Ca < sub > 10 </ sub >( PO < sub > 4 </ sub >)< sub > 6 </ sub >( OH, F, Cl, Br )< sub > 2 </ sub >, and the crystal unit cell formulae of the individual minerals are written as Ca < sub > 10 </ sub >( PO < sub > 4 </ sub >)< sub > 6 </ sub >( OH )< sub > 2 </ sub >, Ca < sub > 10 </ sub >( PO < sub > 4 </ sub >)< sub > 6 </ sub >( F )< sub > 2 </ sub >, Ca < sub > 10 </ sub >( PO < sub > 4 </ sub >)< sub > 6 </ sub >( Cl )< sub > 2 </ sub > and Ca < sub > 10 </ sub >( PO < sub > 4 </ sub >)< sub > 6 </ sub >( Br )< sub > 2 </ sub >.

* Calcium permanganate ( Ca ( MnO < sub > 4 </ sub >)< sub > 2 </ sub >) is used in liquid rocket propellant, textile production, as a water sterilizing agent and in dental procedures.

The active ingredients are monocalcium aluminate CaAl < sub > 2 </ sub > O < sub > 4 </ sub > ( CaO · Al < sub > 2 </ sub > O < sub > 3 </ sub > or CA in Cement chemist notation, CCN ) and mayenite Ca < sub > 12 </ sub > Al < sub > 14 </ sub > O < sub > 33 </ sub > ( 12 CaO · 7 Al < sub > 2 </ sub > O < sub > 3 </ sub >, or C < sub > 12 </ sub > A < sub > 7 </ sub > in CCN ).

LaGuardia took office on March 4, 1917 but soon was commissioned in the United States Army Air Service ; he rose to the rank of major in command of a unit of Ca. 44 bombers on the Italian-Austrian front in World War I. LaGuardia resigned his seat in Congress on December 31, 1919.

;< sup > 226 </ sup > Ra (< sup > 48 </ sup > Ca, xn )< sup > 274 − x </ sup > Hs ( x = 4 )