[Chemistry Class Notes] on Tellurium Pdf for Exam

Tellurium Element

The Tellurium element was discovered by Franz Muller Von Reichenstein. Te in the periodic table belongs to group 16. It is a brittle, slightly radioactive, rare metalloid that is silver-white. Tellurium is chalcogen, which is chemically related to selenium and sulfur. It is also discovered as elemental crystals in indigenous form. In the Universe as a whole, Tellurium is much more abundant than on Earth.

When burning in the sunlight, Tellurium delivers a greenish-blue flame. It does not dissolve in water or hydrochloric acid or react with it but dissolves in nitric acid. 

There’s no biological function for Tellurium. Some fungi, however, use it as a sulfur replacement.

Tellurium is discovered by Franz muller Von Reichenstein.

Physical Properties of Tellurium

Tellurium has two crystalline and amorphous allotropes. Tellurium is silvery-white when crystalline, with a metallic luster. It is a metalloid that is porous and quickly pulverized. Amorphous tellurium is a black-brown powder prepared by precipitating it from a solution of telluric acid or telluric acid  Tellurium is a semiconductor that, depending on atomic orientation, exhibits a higher electrical conductivity in some directions; when exposed to light (photoconductivity), the conductivity increases slightly. Tellurium is corrosive to copper, iron, and iron when molten.

Tellurium Symbol-Te

Tellurium atomic number-52

Tellurium atomic mass-127.6 g.mol-1

Electronic configuration- [ Kr ] 4d10 5s25p4

Tellurium Uses

1. Metallurgy is the largest consumer of tellurium in iron, stainless steel, copper, and lead alloys. The combination of steel and copper creates an alloy that is more machinable than elsewhere. It is alloyed into cast iron for spectroscopy, where the presence of free electrically conductive graphite appears to interfere with the results of spark emission testing. Tellurium in lead increases strength and longevity and reduces the corrosive action of sulfuric acid.

2. Tellurium shows up in a number of popular photocathodes used in solar-blind photomultiplier tubes and for high brightness photoinjectors driving modern particle accelerators. The Cs-Te photocathode, which is primarily Cs2Te, has a 3.5 eV photoemission threshold and exhibits a rare combination of high quantum efficiency (>10%) and high durability in poor vacuum environments.

3. For ceramics, Tellurium compounds are used as pigments. 

4. The optical refraction of glass typically used in glass optical fibers for telecommunication is greatly improved by selenides and tellurides. 

5. Selenium and tellurium mixtures are used with barium peroxide as an oxidizer in the electric blasting cap delay powder.

6. Instead of sulfur or selenium, rubber can be vulcanized with tellurium. Improved heat resistance is shown by the rubber developed in this way. 

7. Tellurite agar is used to classify members of the genus corynebacterium, most specifically the pathogen responsible for diphtheria, Corynebacterium diphtheriae.

Did You Know?

Tellurium and tellurium compounds are considered moderately poisonous and need to be treated with caution, while acute poisoning is rare. Tellurium poisoning is especially difficult to treat because the toxicity of tellurium is increased by certain chelating agents used in the treatment of metal poisoning. It is not confirmed that tellurium is carcinogenic.