Difference between revisions of "Tellurium"
(Added element infobox.) |
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| Line 57: | Line 57: | ||
|phase comment= | |phase comment= | ||
|melting point K=722.66 | |melting point K=722.66 | ||
| − | |melting point C= | + | |melting point C=449.51 |
| − | |melting point F= | + | |melting point F=841.12 |
|melting point ref= | |melting point ref= | ||
|melting point comment= | |melting point comment= | ||
|boiling point K=1261 | |boiling point K=1261 | ||
| − | |boiling point C= | + | |boiling point C=988 |
| − | |boiling point F= | + | |boiling point F=1810 |
|boiling point ref= | |boiling point ref= | ||
|boiling point comment= | |boiling point comment= | ||
| Line 111: | Line 111: | ||
|heat fusion 2 ref= | |heat fusion 2 ref= | ||
|heat fusion 2 comment= | |heat fusion 2 comment= | ||
| − | |heat vaporization=114.1 | + | |heat vaporization=114.1 |
|heat vaporization ref= | |heat vaporization ref= | ||
|heat vaporization comment= | |heat vaporization comment= | ||
| − | |heat capacity=25.73 | + | |heat capacity=25.73 |
|heat capacity ref= | |heat capacity ref= | ||
|heat capacity comment= | |heat capacity comment= | ||
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|electronegativity ref= | |electronegativity ref= | ||
|electronegativity comment= | |electronegativity comment= | ||
| − | |ionization energy 1=869.3 | + | |ionization energy 1=869.3 |
|ionization energy 1 ref= | |ionization energy 1 ref= | ||
|ionization energy 1 comment= | |ionization energy 1 comment= | ||
| − | |ionization energy 2=1790 | + | |ionization energy 2=1790 |
|ionization energy 2 ref= | |ionization energy 2 ref= | ||
|ionization energy 2 comment= | |ionization energy 2 comment= | ||
| − | |ionization energy 3=2698 | + | |ionization energy 3=2698 |
|ionization energy 3 ref= | |ionization energy 3 ref= | ||
|ionization energy 3 comment= | |ionization energy 3 comment= | ||
| Line 156: | Line 156: | ||
|ionization energy ref= | |ionization energy ref= | ||
|ionization energy comment= | |ionization energy comment= | ||
| − | |atomic radius=140 | + | |atomic radius=140 |
|atomic radius ref= | |atomic radius ref= | ||
|atomic radius comment= | |atomic radius comment= | ||
| Line 162: | Line 162: | ||
|atomic radius calculated ref= | |atomic radius calculated ref= | ||
|atomic radius calculated comment= | |atomic radius calculated comment= | ||
| − | |covalent radius=138±4 | + | |covalent radius=138±4 |
|covalent radius ref= | |covalent radius ref= | ||
|covalent radius comment= | |covalent radius comment= | ||
| − | |Van der Waals radius=206 | + | |Van der Waals radius=206 |
|Van der Waals radius ref= | |Van der Waals radius ref= | ||
|Van der Waals radius comment= | |Van der Waals radius comment= | ||
| Line 180: | Line 180: | ||
|speed of sound ref= | |speed of sound ref= | ||
|speed of sound comment= | |speed of sound comment= | ||
| − | |speed of sound rod at 20=2610 | + | |speed of sound rod at 20=2610 |
|speed of sound rod at 20 ref= | |speed of sound rod at 20 ref= | ||
|speed of sound rod at 20 comment= | |speed of sound rod at 20 comment= | ||
| Line 186: | Line 186: | ||
|speed of sound rod at r.t. ref= | |speed of sound rod at r.t. ref= | ||
|speed of sound rod at r.t. comment= | |speed of sound rod at r.t. comment= | ||
| − | |thermal expansion=18 | + | |thermal expansion=18 |
|thermal expansion ref= | |thermal expansion ref= | ||
|thermal expansion comment= | |thermal expansion comment= | ||
| Line 192: | Line 192: | ||
|thermal expansion at 25 ref= | |thermal expansion at 25 ref= | ||
|thermal expansion at 25 comment= | |thermal expansion at 25 comment= | ||
| − | |thermal conductivity=1.97–3.38 | + | |thermal conductivity=1.97–3.38 |
|thermal conductivity ref= | |thermal conductivity ref= | ||
|thermal conductivity comment= | |thermal conductivity comment= | ||
| Line 244: | Line 244: | ||
|Vickers hardness ref= | |Vickers hardness ref= | ||
|Vickers hardness comment= | |Vickers hardness comment= | ||
| − | |Brinell hardness=180–270 | + | |Brinell hardness=180–270 |
|Brinell hardness ref= | |Brinell hardness ref= | ||
|Brinell hardness comment= | |Brinell hardness comment= | ||
Revision as of 23:22, 17 March 2016
 Metallic tellurium, diameter 3.5 cm | |||||||
| General properties | |||||||
|---|---|---|---|---|---|---|---|
| Name, symbol | Tellurium, Te | ||||||
| Appearance |
silvery lustrous gray (crystalline), brown-black powder (amorphous) | ||||||
| Tellurium in the periodic table | |||||||
| |||||||
| Atomic number | 52 | ||||||
| Standard atomic weight (Ar) | 127.6 | ||||||
| Group, block | , -block | ||||||
| Period | period 4 | ||||||
| Electron configuration | [Kr] 4d10 5s2 5p4 | ||||||
per shell | 2, 8, 18, 18, 6 | ||||||
| Physical properties | |||||||
| silvery-gray | |||||||
| Phase | solid | ||||||
| Melting point | 722.66 K (449.51 °C, 841.12 °F) | ||||||
| Boiling point | 1261 K (988 °C, 1810 °F) | ||||||
| Density near r.t. | 6.24 g/cm3 | ||||||
| when liquid, at | 5.70 g/cm3 | ||||||
| Heat of fusion | 17.49 kJ/mol kJ/mol | ||||||
| Heat of | 114.1 kJ/mol | ||||||
| Molar heat capacity | 25.73 J/(mol·K) | ||||||
| pressure | |||||||
| Atomic properties | |||||||
| Oxidation states | 6, 5, 4, 3, 2, 1, −1, −2 a mildly acidic oxide | ||||||
| Electronegativity | Pauling scale: 2.1 | ||||||
| energies |
1st: 869.3 kJ/mol 2nd: 1790 kJ/mol 3rd: 2698 kJ/mol | ||||||
| Atomic radius | empirical: 140 pm | ||||||
| Covalent radius | 138±4 pm | ||||||
| Van der Waals radius | 206 pm | ||||||
| Miscellanea | |||||||
| Crystal structure | | ||||||
| Speed of sound thin rod | 2610 m/s (at 20 °C) | ||||||
| Thermal expansion | 18 µm/(m·K) | ||||||
| Thermal conductivity | 1.97–3.38 W/(m·K) | ||||||
| Magnetic ordering | diamagnetic | ||||||
| Mohs hardness | 2.25 | ||||||
| Brinell hardness | 180–270 MPa | ||||||
| CAS Registry Number | 13494-80-9 | ||||||
| History | |||||||
| Naming | after Roman Tellus, deity of the Earth | ||||||
| Discovery | Franz-Joseph Müller von Reichenstein (1782) | ||||||
| First isolation | Martin Heinrich Klaproth | ||||||
| Most stable isotopes | |||||||
| |||||||
Contents
Properties
Chemical
It is usually found in -2, +2, +4 and +6 oxidation states. It has chemical properties similar to selenium, being dissolved by sulphuric and nitric acid and potassium hydroxide solutions but not in water. It corrodes copper, iron and stainless steel when it's molten. It reacts with oxygen in air, hydrogen and with halogens. It burns with a blueish grey flame. Although being mildly toxic, it is infamous for making you smell really bad so don´t handle it without correct safety equipment.
Physical
Tellurium is a whitish-silvery solid, crystalline element which has a nice, metallic luster. It's a brittle and easily powderized metalloid. It's a good semiconductor, and conductivity increases slightly when exposed to light. It melts at 450 ºC and boils at almost 1000 ºC.
Availability
Tellurium is one of the rarest stable elements on Earth's crust. Applications are scarce, most commonly used in electronics and solar panels. Prices are high and it has few uses for home chemists, in addition to collecting elements.
Production
Tellurium can be prepared by reducing tellurium compounds.
Projects
- Make tellurium dioxide
- Make sodium tellurite
Handling
Safety
Wear appropriate protection when handling it or it's compounds. Certain compounds such as cadmium telluride are highly toxic.
When small amounts are ingested, tellurium and its compounds are metabolized to dimethyl telluride, causing a foul garlic-like odor named "tellurium breath".
Storage
Tellurium should be stored in closed containers.
Disposal
It is best to try to recycle it.
