why is potassium called that in English and Potasio in Spanish, but it's Latin name is kalium and German uses the Latin word?
The difference comes from two competing names that appeared when the element was discovered in the early 1800s, and different language groups adopted different ones.
The English word comes from potash, the material from which the element was first isolated in 1807 by the chemist Humphry Davy. (Wikipedia)
- Potash literally meant “pot ashes.”
- It referred to the old method of extracting potassium salts by leaching wood ashes in pots and evaporating the solution. (Wikipedia)
So Davy named the element potassium after the substance it came from.
Languages that followed this naming tradition include:
- English: potassium
- Spanish: potasio
- French: potassium
- Italian: potassio
All derive from potash → potassium.
Around the same time, German chemists proposed a different name:
- From kali, meaning alkali salts derived from ashes.
- This ultimately comes from the Arabic al-qalyah, meaning “plant ashes.” (EGU Blogs)
The Latinized scientific form became kalium, proposed by German chemists such as Martin Klaproth and later promoted by Berzelius. (Wikipedia)
Languages that adopted this naming tradition include:
- German: Kalium
- Dutch: Kalium
- Swedish / Norwegian / Danish: Kalium
- many Slavic and Eastern European languages
The periodic table symbol comes from the Latin name kalium, even in languages that say “potassium.” (Wikipedia)
This is similar to other elements:
- Sodium → Na (from Latin natrium)
- Iron → Fe (from ferrum)
Spanish and most Romance languages simply adopted the potassium/potash-derived name rather than the German/Latin kalium version.
In short: Two historical naming traditions existed:
- Potash → potassium → potasio (English/French/Romance tradition)
- Kali → kalium (Germanic/scientific tradition)
Both refer to the same element, but the symbol K preserves the kalium lineage.