LANTHANIDE

Noun

lanthanide (plural lanthanides)

(chemistry) Any of the 14 rare earth elements from cerium (or from lanthanum) to lutetium in the periodic table; because their outermost orbitals are empty, they have very similar chemistry; below them are the actinides.

Usage notes

• According to IUPAC - "Although lanthanoid means 'like lanthanum' and so should not include lanthanum, lanthanum has become included by common usage. Similarly, actinoid. The ending 'ide' normally indicates a negative ion, and therefore lanthanoid and actinoid are preferred to lanthanide and actinide. However, lanthanide and actinide are still allowed owing to wide current use."

Synonyms

• lanthanate (obsolete)

• lanthanoid (including lanthanum)

• lanthanon (proposed to avoid confusion with the usual meaning in chemistry of -ide)

• rare-earth element

Source: Wiktionary



RESET




Word of the Day

20 June 2025

MODEST

(adjective) marked by simplicity; having a humble opinion of yourself; “a modest apartment”; “too modest to wear his medals”


coffee icon

Coffee Trivia

In the 18th century, the Swedish government made coffee and its paraphernalia (including cups and dishes) illegal for its supposed ties to rebellious sentiment.

coffee icon