lanthanum
C2 (Very low frequency, technical/specialist)Technical, Scientific, Formal
Definition
Meaning
A soft, silvery-white metallic chemical element, the first of the lanthanide series in the periodic table, with atomic number 57.
A rare-earth element used in catalysts, alloys, and specialised optical and electronic applications due to its unique properties.
Linguistics
Semantic Notes
The term refers specifically to a chemical element. Its usage is almost exclusively confined to chemistry, physics, materials science, and related technical fields. It is not used metaphorically.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Pronunciation differs (see IPA). Spelling is identical.
Connotations
None beyond its technical denotation.
Frequency
Equally rare in both varieties, appearing only in highly specialised contexts.
Vocabulary
Collocations
Grammar
Valency Patterns
Lanthanum is used in [application].The compound contains [amount] of lanthanum.Lanthanum reacts with [element/compound].Vocabulary
Synonyms
Neutral
Weak
Usage
Context Usage
Business
Used only in reports or discussions within the mining, catalysis, or advanced materials sectors.
Academic
Common in chemistry, physics, materials science, and geology research papers and textbooks.
Everyday
Virtually never used.
Technical
The primary domain of use. Appears in specifications, patents, lab reports, and technical manuals for optics, electronics, and metallurgy.
Examples
By Part of Speech
adjective
British English
- The lanthanum component of the catalyst was analysed.
- A lanthanum-doped crystal was synthesised.
American English
- The lanthanum content of the ore was measured.
- They studied lanthanum-based phosphors.
Examples
By CEFR Level
- Lanthanum is a soft, shiny metal.
- This mineral contains small amounts of lanthanum.
- The chemist separated lanthanum from the other rare-earth elements in the sample.
- Lanthanum oxide is a key component in certain types of optical glass.
- Alloys containing lanthanum are used in the production of flints for lighters.
Learning
Memory Aids
Mnemonic
Think: 'LANTHanum is the FIRST in line' – it's the first element in the lanthanide series on the periodic table.
Conceptual Metaphor
None applicable; it is a concrete, scientific term.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'лантана' (lantana, a plant).
- The Russian term is 'лантан'. It is a direct cognate, so the main trap is spelling/pronunciation.
- The '-um' ending is typical for elements in English (cf. aluminium, platinum).
Common Mistakes
- Misspelling as 'lanthanam', 'lantanum', or 'lanthanide' (which is the series name).
- Incorrect stress placement (e.g., /lænˈθeɪnəm/).
- Using it as a general term for all rare-earth elements.
Practice
Quiz
In which field is the term 'lanthanum' most commonly used?
FAQ
Frequently Asked Questions
Elemental lanthanum metal is flammable and its compounds should be handled with care, but it is not considered highly toxic compared to other metals.
Common uses include catalysts in oil refining, carbon arc lights for studio lighting and projectors, battery electrodes, and as an additive in special optical glasses.
The term 'rare-earth' is historical; these elements are not especially rare in the Earth's crust, but they are typically found dispersed and are difficult to separate from one another.
Naturally occurring lanthanum is almost entirely the stable isotope La-139. Trace amounts of radioactive La-138 exist but pose no significant hazard.