calcium
(Ca)
(element, Ca, atomic number 20)
Calcium (Ca) is the element with atomic number 20, symbol Ca.
Its most common isotope has mass number 40,
but 42, 43, and 44 are more stable and 46 is stable as well.
It is the fifth most common element in the Earth's crust.
Calcium is commonly detected in stars,
F-type stars and G-type stars showing ionized calcium, e.g.,
the Sun, which (among the Fraunhofer lines)
has strong absorption lines
of singly ionized calcium (Ca II),
including the (Fraunhofer) H line (396.85 nm)
and K line (393.37 nm).
K-type stars and M-type stars often show neutral
calcium (Ca I).
(element,metal,chemistry)
Further reading:
https://en.wikipedia.org/wiki/Calcium
https://en.wikipedia.org/wiki/Calcium_triplet
http://hyperphysics.phy-astr.gsu.edu/hbase/pertab/ca.html
https://www.rsc.org/periodic-table/element/20/calcium
https://physics.nist.gov/PhysRefData/Handbook/Tables/calciumtable2.htm
https://www.oxfordreference.com/display/10.1093/oi/authority.20110803095919178
Referenced by pages:
alpha element
Am star
CAI
calcium-rich gap transient (ca-rich gap transient)
carbonate-silicate cycle
cosmic dust
element
Fraunhofer lines
Herbig AeBe star (HAeBe)
K-line
Lick Observatory Calcium Line Survey (LkCl)
rare designator prefixes
T-Tauri star (TTS)
Type Ia supernova
Wilson-Bappu effect
Index