Calcium

Pronunciation

• US IPA: /ˈkælsiÉ™m/

Origin

A New Latin word derived by Sir Humphry Davy in 1808, from Latin calx ("lime", "limestone") because it occurs in limestone.

Chambers Dictionary of Etymology, Robert K. Barnhart (ed.), Chambers, 1988

Noun

1. A chemical element, atomic number 20, that is an alkaline earth metal and occurs naturally as carbonate in limestone and as silicate in many rocks.
• 2013, Katie L. Burke, In the News, Oxygen levels on Earth skyrocketed 2.4 billion years ago, when cyanobacteria evolved photosynthesis:.... The evolutionary precursor of photosynthesis is still under debate, and a new study sheds light. The critical component of the photosynthetic system is the “water-oxidizing complex”, made up of manganese atoms and a calcium atom.
2. (countable) An atom of this element.

Derived terms

Related terms