calcium
Let an agent identify calcium and its properties, relay isotopes, compounds, production and uses from reference sources, describe biological and dietary roles in general terms, and distinguish the element from its compounds and supplements.
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 calcium and its properties, relay isotopes, compounds, production and uses from reference sources, describe biological and dietary roles in general terms, and distinguish the element from its compounds and supplements.
A chemical element with symbol Ca and atomic number 20, a reactive alkaline earth metal and the fifth most abundant element in the Earth crust, occurring in limestone, gypsum and other minerals, essential to life as the main mineral of bones, teeth and shells and as a signalling ion in cells, and used in its compounds for cement, lime, plaster and steelmaking and as the metal in alloys and reduction; calcium has five stable isotopes, the long-lived calcium-48 and radioactive isotopes such as calcium-41, 45 and 47, with dietary calcium important for bone health.
What it is for: Construction materials, metallurgy and biological function.
It can be relay properties and isotopes; explain compounds and uses; relay biological and dietary roles; distinguish from compounds.
Distinguishing features
Abundant in crust
Bone mineral
Signalling ion
Cement and lime basis
What it looks like
A dull grey silvery metal that tarnishes in air.
Physical character
atomic number: 20 Z
standard atomic weight: 40.078 u
melting point: 842 degrees C
calcium in the adult body: about 1-1.2 kg
How it is recognised
Element 20, symbol Ca
Alkaline earth metal of bones, limestone and cement
Calcium carbonate and other compounds are not the metal; magnesium and strontium are neighbouring group members
Related models
is a kind of - in registry terms
is a kind of - in registry terms
forms - in limestone and shells
is essential for - as hydroxyapatite
In practice
Families and kinds
calcium metal
calcium compounds such as carbonate, oxide, hydroxide, sulfate and phosphate
stable isotopes 40, 42, 43, 44 and 46, long-lived calcium-48, and radioactive isotopes such as calcium-34 to 37, 41, 45, 47, 59 and 60
dietary calcium and supplements
calcium in biology as ion and mineral
Identifiers
symbol Ca
CAS 7440-70-2
Standards and regulation
Chemical safety rules for reactive metals
Dietary reference intakes for calcium
Cement and lime product standards
Radiation rules for calcium isotopes in research
Failure modes and hazards
Reactivity with water
Hypercalcaemia and hypocalcaemia
Confusing element with compounds and supplements
Agents giving personal dietary or medical advice
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.calcium
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 calcium is.
Identity.
Properties
Properties.
Properties
Properties.
- What are the physical and chemical properties of calcium? definition
- Is the question about the element, a compound or a supplement? boundary
Isotopes
Isotopes.
Isotopes
Isotopes.
- Which isotopes exist, and how are calcium-41, 45 and 47 used? definition
- Which entry fits the specific isotope? action
Produce Compounds and industry.
Industry.
Compounds
Compounds and materials.
Compounds
Compounds.
- How are limestone, lime, cement, gypsum and other calcium materials produced and used? provenance
- Which entry fits the specific compound? action
Metal
Calcium metal.
Metal
Metal.
- How is calcium metal produced, and where is it used? provenance
- Which references are standard? provenance
Life Biology and diet.
Public health.
Biology
Calcium in the body.
Biology
Biology.
- What roles does calcium play in bones, muscle, nerves and cell signalling? provenance
- Which entry fits calcium in biology? action
Diet
Dietary calcium.
Diet
Diet.
- What do guidelines say about calcium intake, sources and supplements, in general terms? provenance
- Is the user asking for personal dietary or medical advice, which needs a professional? boundary
Context History and environment.
Context.
Discovery
Discovery.
Discovery
Discovery.
- How was calcium isolated by Davy in 1808, and how was its role in life discovered? provenance
- Which entry fits the history of chemistry? action
Environment
Calcium cycle.
Environment
Environment.
- How does calcium cycle through rocks, oceans and organisms? provenance
- Which sources are cited? provenance
What the second pass must settle
- Should calcium carbonate and dietary calcium be separate primary entries?
- How should health guidelines be linked?
- The registry entry has merged aliases naming short-lived isotopes; should they be split off?