Potassium

How to spell potassium

9 letters · 4 syllables

How to pronounce potassium

Say the part in capitals loudest.

What does potassium mean?

1. nounA soft, silvery, highly reactive metallic element (symbol K) whose compounds are essential to plant growth and human nutrition.

Potassium in a sentence

• Bananas are a good dietary source of potassium.

• The blood test measured her potassium and sodium levels.

Where does potassium come from?

Language of origin: Germanic

Potassium is a coined scientific name that the English chemist Sir Humphry Davy gave to the metal he first isolated in 1807. He built it on the everyday English word potash, which itself is a plain compound of 'pot' and 'ash', describing the alkaline substance obtained by soaking wood ashes in water inside iron pots and then boiling the liquid down. To turn that homely name into a proper element label, Davy added the Latin suffix '-ium', the same ending found in sodium, calcium and magnesium. This is why the metal's chemical symbol is the odd-looking K rather than P: the symbol comes from 'kalium', a separate Latin form derived from the Arabic 'al-qali', meaning the calcined ashes or alkali. The double s in the middle is the main spelling trap, a hangover from the doubled s of 'potash'.

How the word is built

• potass- (from potash, the alkaline residue left in pots after burning plant ashes)
• -ium (Latin suffix naming a chemical element or metal)