Selenium | Wikipedia audio article
Channel: wikipedia tts
Date: 2018-12-08

This is an audio version of the Wikipedia Article:
Selenium


00:01:54 1 Characteristics
00:02:03 1.1 Physical properties
00:04:22 1.2 Optical properties
00:04:43 1.3 Isotopes
00:05:03 2 Chemical compounds
00:05:21 2.1 Chalcogen compounds
00:07:49 2.2 Halogen compounds
00:08:59 2.3 Selenides
00:10:07 2.4 Other compounds
00:10:42 2.5 Organoselenium compounds
00:11:48 3 History
00:14:46 4 Occurrence
00:16:19 5 Production
00:18:40 6 Applications
00:18:49 6.1 Manganese electrolysis
00:19:17 6.2 Glass production
00:19:53 6.3 Alloys
00:20:31 6.4 Lithium–selenium batteries
00:20:55 6.5 Solar cells
00:21:09 6.6 Photoconductors
00:21:34 6.7 Rectifiers
00:21:51 6.8 Other uses
00:23:52 7 Biological role
00:26:29 7.1 Evolution in biology
00:29:31 7.2 Nutritional sources of selenium
00:30:34 7.3 Indicator plant species
00:31:05 7.4 Detection in biological fluids
00:31:53 7.5 Toxicity
00:36:04 7.6 Deficiency
00:36:31 7.7 Controversial health effects
00:37:37 8 See also



Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago.

Learning by listening is a great way to:
- increases imagination and understanding
- improves your listening skills
- improves your own spoken accent
- learn while on the move
- reduce eye strain

Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone.

You can find other Wikipedia audio articles too at:
https://www.youtube.com/channel/UCuKfABj2eGyjH3ntPxp4YeQ

You can upload your own Wikipedia articles through:
https://github.com/nodef/wikipedia-tts



"The only true wisdom is in knowing you know nothing."
- Socrates



SUMMARY
=======
Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It rarely occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium (from Ancient Greek σελήνη (selḗnē) "Moon") was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium (named for the Earth).
Selenium is found in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known but rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been mostly replaced with silicon semiconductor devices. Selenium is still used in a few types of DC power surge protectors and one type of fluorescent quantum dot.
Selenium salts are toxic in large amounts, but trace amounts are necessary for cellular function in many organisms, including all animals. Selenium is an ingredient in many multivitamins and other dietary supplements, including infant formula.  It is a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase (which indirectly reduce certain oxidized molecules in animals and some plants). It is also found in three deiodinase enzymes, which convert one thyroid hormone to another. Selenium requirements in plants differ by species, with some plants requiring relatively large amounts and others apparently requiring none.