thán khí
Definition
- Noun (Archaic/Chemistry):
- Carbonic acid gas: An archaic Vietnamese term for carbon dioxide (CO₂), a colorless, odorless gas produced by respiration and combustion, and consumed by plants in photosynthesis.
- Choke-damp: In historical mining contexts, it could refer to air vitiated by carbon dioxide, which is unable to support life.
Usage Examples
- Noun:
- Thực vật hấp thụ thán khí và nhả ra dưỡng khí. (Plants absorb carbonic acid gas and release oxygen.)
- Các nhà khoa học thế kỷ 18 đã nghiên cứu về tính chất của thán khí. (18th-century scientists studied the properties of carbonic acid gas.)
Advanced Usage
- This term is largely obsolete in modern Vietnamese scientific and everyday language. It has been almost entirely replaced by the modern chemical term "cacbon đioxit" or "khí CO₂".
- It is primarily encountered in historical texts, classical literature, or in fixed phrases from earlier periods.
Variants and Related Words
- Cacbon đioxit (n): The modern, standard term for carbon dioxide (CO₂).
- Khí CO₂ (n): The common abbreviated form for carbon dioxide gas.
- Dưỡng khí (n, archaic): The archaic counterpart meaning "oxygen" (literally, "nourishing gas").
Synonyms
- Carbon dioxide: The modern, standard English equivalent.
- Carbonic acid gas: The direct, literal translation of the archaic term.
- CO₂: The chemical formula.
Notes on Usage
- "Thán khí" is a compound Sino-Vietnamese word: "thán" (carbon) + "khí" (gas). It is a direct calque of the older Western chemical term.
- It belongs to a set of archaic terms for gases, such as "dưỡng khí" (oxygen) and "than khí" (a term sometimes used for nitrogen or foul air), which are no longer standard.
- When translating or explaining historical documents, "carbonic acid gas" or "carbon dioxide" are appropriate English equivalents. For contemporary contexts, only "carbon dioxide" or "CO₂" should be used.