selenium
Let an agent identify selenium and its properties, relay its nutritional and toxicological roles from authoritative sources, explain production and uses, and distinguish it from tellurium and sulfur.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent identify selenium and its properties, relay its nutritional and toxicological roles from authoritative sources, explain production and uses, and distinguish it from tellurium and sulfur.
A chemical element with symbol Se and atomic number 34, a metalloid in the oxygen group with grey metallic and red non-metallic allotropes, photoconductive and semiconducting; selenium is an essential trace nutrient in selenoproteins, toxic in excess, recovered mainly from copper refining, and used in glass, pigments, electronics, photocopiers historically, and dietary supplements, with six natural isotopes.
What it is for: Glass, electronics, pigments, nutrition and agriculture.
It can be relay properties and isotopes; explain nutrition and toxicity; explain production and uses; distinguish from related elements.
Distinguishing features
Essential and toxic
Photoconductive
Allotropes
Copper refining by-product
What it looks like
A grey metallic solid in its stable form, or red powder and glass in other allotropes.
Physical character
atomic number: 34 Z
standard atomic weight: 78.971 u
melting point: 221 degrees C - grey form
adult recommended intake: about 55 micrograms per day - varies by authority
How it is recognised
Element 34, symbol Se
Metalloid in group 16
Sulfur and tellurium are the neighbouring chalcogens
Related models
is a kind of - in registry terms
is a kind of - group 16
is essential in - such as glutathione peroxidase
is adjacent to - element 33
In practice
Families and kinds
selenium allotropes: grey, red and black
selenium compounds such as selenides and selenites
isotopes from selenium-65 to selenium-95, with six natural and Se-79 long-lived
selenium in nutrition and selenoproteins
Identifiers
symbol Se
CAS 7782-49-2
Standards and regulation
Dietary reference intakes and upper limits
Supplement and food fortification regulations
Occupational exposure limits
Environmental rules for selenium in water
Failure modes and hazards
Deficiency diseases and toxicity from excess
Environmental contamination from mining and agriculture
Agents giving personal supplementation advice
Also called
+2
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.selenium
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Identify What selenium is.
Identity.
Properties
Properties and allotropes.
Properties
Properties.
- What are the properties and allotropes of selenium? definition
- Is the question about selenium or a neighbouring chalcogen? boundary
Isotopes
Isotopes.
Isotopes
Isotopes.
- Which isotopes exist, and which are stable or of interest? definition
- Which entry fits the specific isotope? action
Health Nutrition and toxicity.
Clinical.
Nutrition
Nutrition.
Nutrition
Nutrition.
- What role does selenium play in the body, and what do dietary references say? provenance
- Is the user asking about personal supplementation, which needs a professional? boundary
Toxicity
Toxicity.
Toxicity
Toxicity.
- What are the effects of deficiency and excess, and what limits apply? provenance
- Which references are standard? provenance
Industry Production and uses.
Supply.
Production
Production.
Production
Production.
- How is selenium recovered, and who produces it, with sources? provenance
- Which sources are cited? provenance
Uses
Uses.
Uses
Uses.
- How is selenium used in glass, pigments, electronics and agriculture? provenance
- Which entry fits a specific use? action
Context Environment and history.
Context.
Environment
Environmental selenium.
Environment
Environment.
- How does selenium move through soils and water, and where is contamination a problem? provenance
- Which entry fits environmental toxicology? action
History
History.
History
History.
- How was selenium discovered by Berzelius in 1817, and how was its role in nutrition found? provenance
- Which entry fits the history of chemistry? action
What the second pass must settle
- Should selenium deficiency and toxicity be separate entries?
- How should dietary standards be linked?
- The registry entry has merged aliases naming isotopes; should they be split off?