27 December 2024
Calcium is a chemical element with atomic number 20 and the symbol Ca. It is a reactive, alkaline earth metal, dull gray or silver in color with a yellow tint. When exposed to air it forms a dark oxide layer on the surface. Calcium is essential for life as we know it, used to build bones and teeth and in the muscular, circulatory, and digestive systems. It is also widely used in industry.
Calcium compounds were known to the ancients, but the element was first isolated and named by Humphry Davy in 1808. The name has a straightforward etymology, from the Latin calx (limestone) + -ium; limestone being calcium carbonate. Davy proposed the name in a lecture to the Royal Society of London on 30 June 1808:
These new substances will demand names; and on the same principles as I have named the bases of the fixed alkalies, potassium and sodium, I shall venture to denominate the metals from the alkaline earths barium, strontium, calcium, and magnium.
Sources:
Davy, Humphry. “Electro-Chemical Researches, on the Decomposition of the Earths; with Observations on the Metals obtained from the Alkaline Earths, and on the Amalgam Procured from Ammonia” (30 June 1808). Philosophical Transactions of the Royal Society of London, 1808, 333–370 at 346. HathiTrust Digital Archive.
Miśkowiec, Pawel. “Name Game: The Naming History of the Chemical Elements—Part 1—From Antiquity till the End of 18th Century.” Foundations of Chemistry. 1 November 2022. DOI: 10.1007/s10698-022-09448-5.
Oxford English Dictionary, second edition, 1989, s.v. calcium, n.
Photo credit: Brian C. Goss, 2006. Wikimedia Commons. Public domain image.