Science & TechnologyGreek → English
Amphoteric
/ˌæmfəˈtɛrɪk/adjective
Able to act as either an acid or a base.
The Greek roots
ἀμφότερος
amphóteros
both of two
Literally: “both of two”
Follow a root:ἀμφότερος1 word
The story of the word
Water is the household case: it hands a proton to ammonia and takes one from hydrochloric acid, behaving as base and acid by turns. ἀμφότερος means both of the two, built on the ἀμφί that gives an amphibian its two lives and an amphitheatre its seats on either side. Nineteenth-century chemists wanted a label for oxides like aluminium's, which dissolve in acid and in alkali alike; amino acids inherited the word later, since each one carries an acid group and a base group on the same molecule.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 19th century
Same family
amphibianamphitheatreamphoraamphibious
In a sentence
Zinc oxide is amphoteric, which is why it will go into solution in either direction.
The exam asked which of the three oxides was amphoteric and why.