Proprietăți

CAS Number7440-47-3
PubChem CID23976
Rază atomică128
Volum molar7,23
Masă atomică51,996
Blocd
Punct de fierbere2.671
Bulk Modulus
CategorieMetale de tranziție
Structură cristalinăCorp Centrat Cubic
CuloareArgint
Rază de covalență139
Densitate7,15
Electrical Resistivity
Configurație electronică[Ar] 3d5 4s1
Electroni pe nivelul de energie2, 8, 13, 1
Electronegativitate1,66
Electrons24
Grupă6
Energie de fuziune20,5
Energie de evaporare339
Potențial de ionizare6,766
Magnetic Ordering
Magnetic Susceptibility
Masa51,996
Mass Number24
Punct de topire1.907
NumeCrom
Neutroni28
Număr atomic52
Număr de oxidare-2, -1, 1, 2, 3, 4, 5, 6
Perioadă4
FazăSolid
Poisson Ratio
Protoni24
Shear Modulus
Căldură specifică0,449
SimbolCr
Conductivitate termică0,937
Van der Waals radius
Young's Modulus
Abundență naturală
Abundența în scoarța Pământului0.014%
Abundența în Univers0.0015%
Cr Crom 24 51.9961 6 4 d 24 1857.0 2672.0 [Ar] 3d5 4s1 2 8 13 1 7.19 0.014% Silver Cubic: Body centered 1.7 1.65 {"1":"652.9","2":"1590.6","3":"2987","4":"4743","5":"6702","6":"8744.9","7":"15455","8":"17820","9":"20190","10":"23580","11":"26130","12":"28750","13":"34230","14":"37066","15":"97510","16":"105800","17":"114300","18":"125300","19":"134700","20":"144300","21":"157700","22":"166090","23":"721870","24":"761733"} 653 64.3 127 +3,2,6 1.3 7.23 20.0 339.5 0.449 93.7 393.K 0 Solid, Antiferromagnetic, Conductor, TransitionMetal, Metal, Stable, Natural KROH-mi-em Very hard, crystalline, steel-gray metal. The pure metal has a blue-white color. It is hard, brittle and corrsion-resistant at normal temperatures. Used to make stainless steel. It gives the color to rubies and emeralds. Iron-nickel-chromium alloys in various percentages yield an incredible variety of the most important metals in modern technology. Chromite [Fe,Mg(CrO4)] is its most important mineral. Produced commercially by heating its ore in the presence of silicon or aluminium. lzRb4zmGvNU Chromium
In 1800, Sir Humphry Davy thought silica to be a compound and not an element; but in 1811, Gay Lussac and Louis Jacques Thénard probably prepared impure amorphous silicon by heating potassium with silicon tetrafluoride.

In 1824 Jöns Jakob Berzelius prepared amorphous silicon by the same general method.

Henri Deville in 1854 first prepared crystalline silicon, the second allotropic form of the element. Din cuvântul latin silex, silex, cremene 24 1797 Louis-Nicholas Vauquelin France From the Greek word "chroma" meaning "colour", named for the many coloured compounds known for chromium.

Isotopes of Silicon

Standard Atomic Weight

51.9961(6)

Izotopi stabili

50Cr 52Cr 53Cr 54Cr

Izotopi instabili

42Cr 43Cr 44Cr 45Cr 46Cr 47Cr 48Cr 49Cr 51Cr 55Cr 56Cr 57Cr 58Cr 59Cr 60Cr 61Cr 62Cr 63Cr 64Cr 65Cr 66Cr 67Cr

If breathed in as a fine silica/silicate dust, it may cause chronic respiratory problems
Silicon also has the unusual property that it expands as it freezes
In the form of sand and clay it is used to make concrete and brick; it is a useful refractory material for high-temperature work, and in the form of silicates it is used in making enamels, pottery, etc.

Silica, as sand, is a principal ingredient of glass.

Silicon chips are the basis of modern electronic and computing.

Silicon carbide, more commonly called carborundum is used in abrasives.