Calcium

 

Name/Origin: Calcium- The Latin word calx, which means lime. In addition, calcium is the fifth most abundant element in the earth’s crust.     
Classification: alkaline earth metal

Symbol: Ca

 

Physical Properties

 

Description: Calcium is obtained from chalk, limestone, and marble. It is a soft metal with a cubic crystalline structure. Calcium has six stable and several radioactive isotopes. A malleable and ductile metal, calcium is silvery-white when pure, but it rapidly tarnishes to yellow on exposure to air. Calcium is fifth in abundance among the elements in the earth's crust, but it is not found uncombined in nature.

Crystal Structure: cubic crystalline structure                       

                                        

Color: silver-white
Texture:
silver-white, and soft metal   
Intensive characteristics:                                                           
       Melting point: 890ēC
       Boiling point: 1, 484ēC

       Density: 1.55 grams per cubic centimeter  

 

 

Atomic structure:
Shell Structure: 2.8.8.2.
Atomic number: 20
Atomic weight: 40.08        
                   Electron configuration: 1s2 2s2 2p6 3s2 3p6 4s                                          
    
 

 

Isotopes

Isotope Half Life
Ca-40 Stable
Ca-41 103000.0 years
Ca-42 Stable
Ca-43 Stable
Ca-44 Stable
Ca-45 162.7 days
Ca-46 Stable
Ca-47 4.5 days
Ca-48 Stable
Ca-49 8.7 minutes

 

 

Chemical Properties


*Calcium is very active.
Calcium is prepared by the electrolysis where it is fused with calcium chloride and a small amount of calcium fluoride. Calcium forms alloys with aluminum, lead, or copper. In preparing other metals, such as thorium and uranium, calcium goes through reduction and manufactured vacuum tubes to remove residual gases.
 

COMPOUNDS

*Although calcium is the fifth most abundant element in the earth's crust, it is not found in its pure elemental form. Its compounds are widely distributed in : Iceland Spar, Marble, Limestone, Fluorite, and Garnet.
*Tremolite, which is a form of asbestos, is naturally occurring compound in calcium, magnesium, silicon, and oxygen.
*
Calcite is a mineral consisting largely of calcium carbonate (CaCO3). Compared to quartz, Calcite is the most abundant mineral in the earth's crust. It has a hexagonal structure and  is noted for its wide variety of crystalline forms. It also occurs in massive or cryptocrystalline formations.

Sources: Calcium is obtained from chalk, limestone, and marble.
Toxicity:
When the calcium mineral intake is excessive the effects are:
- body may not be able to absorb iron and zinc
- Poor kidney
function
- Kidney Stones

 

Uses in Compound Form:

   *Calcium compounds are used in the manufacture of iron and steel, cements and plasters, as well as gypsum wall board. It is also used prepare calcium cyanide, which is used as a fertilizer. In its mineral form, it is important in the formation of bones and teeth, important for normal functioning kidney, assists in normal blood clotting, and lowers blood pressure.  In the human adult the bone calcium is in the form of phosphate and carbonate salts.

History
Calcium compounds have been used to make mortar, which is a mixture of cement and lime, by the ancient Egyptians, Greeks, and Romans. Bu it was Sir Humphrey Davy, an English chemist, who was the first to isolate calcium1808 in London, UK. Davy isolated calcium by breaking up lime in mercury by passing an electric current through it. This process is called electrolysis. Because of the electrolysis, he was able to take out the calcium in the lime. Then he was able to isolate calcium, but not as a pure metal. Because this is a difficult process, calcium was not available in large amounts until the 1900's.

Health

 

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