| Zinc - Zn
CAS: 7440-66-6 Description: Hard, brittle, shiny, bluish-white metal Classification: Transition Metal Date of Discovery: 1746 Discoverer: Andreas Marggraf Name Origin: German zin, "tin" |
|
|
Atomic Number: 30
Number of Neutrons: 35 Atomic Mass: 65.39 amu Melting Point: 419.58 °C Boiling Point: 907.0 °C Density (293 K): 7.133 g/cm3 Atomic volume: 9.2 cm3/mol Electrical resistivity: 0.166 10-6/cm 
Thermal conductivity: 1.16 W/cmK Enthalpy of atomization: 129.7 kJ/mol Enthalpy of vaporization: 115.30 kJ/mol Enthalpy of fusion: 7.32 kJ/mol Specific heat capacity: 0.39 J/gK |
Energy levels: 2-8-18-2
Electron configuration: [Ar]3d104s2 Crystal Structure: Hexagonal Atomic radius: 1.53 Å Covalent radius: 1.25 Å Oxidation States: +2 Electronegativity, Pauling: 1.65 Electron affinity: not stable First ionization energy: 9.394 eV 2nd ionization energy: 17.964 eV 3rd ionization energy: 39.722 eV Polarizability: 7.1 10-24cm3 |
| Isotope | Natural Abundance | Atomic Mass | Half-life | Decay Mode | Spin |
| 57Zn | 56.9649 | 0.04 s |  +, p |
(7/2-) | |
| 59Zn | 58.94927 | 183 ms | +, p |
3/2- | |
| 60Zn | 59.94183 | 2.40 m | +; EC |
0+ | |
| 61Zn | 60.93951 | 1.485 m | + |
3/2- | |
| 62Zn | 61.93433 | 9.22 h | +; EC |
0+ | |
| 63Zn | 62.933215 | 38.5 m | +; EC |
3/2- | |
| 64Zn | 48.6(3) | 63.929146 | Stable | 0+ | |
| 65Zn | 64.929245 | 243.8 d | +; EC |
5/2- | |
| 66Zn | 27.9(2) | 65.926036 | Stable | 0+ | |
| 67Zn | 4.1(1) | 66.927131 | Stable | 5/2- | |
| 68Zn | 18.8(4) | 67.924847 | Stable | 0+ | |
| 69mZn | 13.76 h | IT | 9/2+ | ||
| 69Zn | 68.926553 | 56 m | - |
1/2- | |
| 70Zn | 0.6(1) | 69.925325 | Stable | 0+ | |
| 71mZn | 3.97 h | - |
9/2+ | ||
| 71Zn | 70.92773 | 2.4 m | - |
1/2- | |
| 72Zn | 71.92686 | 46.5 | - |
0+ | |
| 73mZn | 6 s | (7/2+) | |||
| 73Zn | 72.92978 | 24 s | - |
(1/2-) | |
| 74Zn | 73.92946 | 1.60 m | - |
||
| 75Zn | 74.9329 | 10.2 s | - |
||
| 76Zn | 75.9334 | 5.7 s | - |
||
| 77mZn | 1.0 s | - |
(1/2-) | ||
| 77Zn | 76.9371 | 2.1 s | - |
||
| 78Zn | 77.9386 | 1.5 s | - |
||
| 79Zn | 78.9421 | 1.0 s | - |
||
| 80Zn | 79.9444 | 0.54 s | - |
||
| 81Zn | 80.9505 | 0.29 s | - |
||
|
Centuries before zinc was recognized as a distinct element, zinc ores were used for making brass. Tubal-Cain, seven generations from Adam, is mentioned as being an "instructor in every artificer in brass and iron." An alloy containing 87% zinc has been found in prehistoric ruins in Transylvania. Metallic zinc was produced in the 13th century A.D. in India by reducing calamine with organic substances such as wool. The metal was rediscovered in Europe by Marggraf in 1746, who showed that it could be obtained by reducing calamine with charcoal. The principal ores of zinc are sphalerite or blende (ZnS), smithsonite (ZnCO3), calamine [ Zn4Si2O7(OH)2 · H2O], franklinite [(Zn,Mn2+,Fe2+)(Fe3+,Mn3+)2O4], and zincite (ZnO). Zinc can be obtained by roasting its ores to form the oxide and by reduction of the oxide with coal or carbon, with subsequent distillation of the metal. Other methods of extraction are possible. Naturally occurring zinc contains five stable isotopes. Twenty-three other unstable isotopes and isomers are recognized. Zinc is a bluish-white, lustrous metal. It is brittle at ordinary temperatures but malleable at 100 to 150 °C. It is a fair conductor of electricity, and burns in air at high red heat with evolution of white clouds of the oxide. The metal is employed to form numerous alloys with other metals. Brass, nickel silver, typewriter metal, commercial bronze, spring bronze, German silver, soft solder, and aluminum solder are some of the more important alloys. Large quantities of zinc are used to produce die castings, used extensively by the automotive, electrical, and hardware industries. An alloy called Prestal®, consisting of 78% zinc and 22% aluminum is reported to be almost as strong as steel but as easy to mold as plastic. It is said to be so plastic that it can be molded into form by relatively inexpensive die casts made of ceramics and cement. It exhibits superplasticity. Zinc is also used extensively to galvanize other metals such as iron to prevent corrosion. Neither zinc nor zirconium is ferromagnetic; but ZrZn2 exhibits ferromagnetism at temperatures below 35 °K. Zinc oxide is a unique and very useful material to modern civilization. It is widely used in the manufacture of paints, rubber products, cosmetics, pharmaceuticals, floor coverings, plastics, printing inks, soap, storage batteries, textiles, electrical equipment, and other products. It has unusual electrical, thermal, optical, and solid-state properties that have not been fully investigated. Lithopone, a mixture of zinc sulfide and barium sulfate, is an important pigment. Zinc sulfide is used in making luminous dials, X-ray and TV screens, and fluorescent lights. The chloride and chromate are also important compounds. Zinc is an essential element in the growth of human beings and animals. Tests show that zinc-deficient animals require 50% more food to gain the same weight as an animal supplied with sufficient zinc. Zinc is not considered to be toxic, but when freshly formed ZnO is inhaled a disorder known as the oxide shakes or zinc chills sometimes occurs. It is recommended that where zinc oxide is encountered good ventilation be provided.
LINKS: American Galvanizers Association American Zinc Association ATSDR - Public Health Statement: Zinc Compton's Online: Zinc The International Lead and Zinc Study Group Zinc Gluconate Lozenges for Treating the Common Cold Zinc Recycling Technology Return
Sources for the information on this website include: Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998. |
|||||