radium sulfate
Low/Very SpecialisedTechnical/Scientific, Historical
Definition
Meaning
A white, insoluble, radioactive crystalline salt of radium, RaSO₄, used historically in radiotherapy.
A chemical compound consisting of radium cations and sulfate anions; historically significant as a standard source for radium-based radiation treatments and luminous paints, now largely obsolete due to safety concerns.
Linguistics
Semantic Notes
Primarily a technical term from chemistry, physics, and medical history. It denotes a specific chemical entity, not a general concept. Its usage is almost entirely confined to professional and historical contexts.
Dialectal Variation
British vs American Usage
Differences
No significant lexical differences. Orthographically, 'sulfate' is standard in British scientific writing, though the older 'sulphate' variant is also common and accepted. American English exclusively uses 'sulfate'.
Connotations
Identical connotations of radioactivity, historical medical use, and hazard.
Frequency
Extremely low frequency in both varieties, appearing only in specialised historical or technical texts.
Vocabulary
Collocations
Grammar
Valency Patterns
[Substance] contains radium sulfate.Radium sulfate was used for [purpose].The [property] of radium sulfate is [adjective].Vocabulary
Synonyms
Neutral
Weak
Vocabulary
Antonyms
Usage
Context Usage
Business
Not applicable.
Academic
Used in historical reviews of radiotherapy, papers on the history of radioactivity, and chemical studies of radium compounds.
Everyday
Virtually never used.
Technical
Used in nuclear chemistry, health physics (regarding legacy contamination), and conservation of historical artefacts (e.g., luminous dials).
Examples
By Part of Speech
noun
British English
- The museum's collection includes a vial of radium sulphate from the 1920s.
- Precipitation of radium sulphate completes the separation process.
American English
- The old factory site was contaminated with radium sulfate.
- Radium sulfate was once encapsulated in needles for interstitial therapy.
adjective
British English
- The radium-sulphate source was carefully shielded.
- They studied the radium sulphate decay chain.
American English
- A radium-sulfate compound was applied to the dials.
- The radium-sulfate contamination required remediation.
Examples
By CEFR Level
- Radium sulfate is a radioactive chemical.
- Old watches sometimes had paint made with radium sulfate.
- Due to its insolubility, radium sulfate could be separated from other elements in the ore.
- The use of radium sulfate in medicine declined after the dangers of radiation were fully understood.
- The crystalline structure of radium sulfate is isomorphous with barite (BaSO₄), which facilitated its initial isolation by the Curies.
- Analyses of historical radium sulfate samples reveal their isotopic purity and specific activity.
Learning
Memory Aids
Mnemonic
Think of 'RADium' for RADioactivity, and 'SULFate' like the mineral gypsum (calcium sulfate), but much more dangerous.
Conceptual Metaphor
A SEALED LEGACY: Radium sulfate is conceptualised as a locked-away historical agent, a powerful but contained relic of past scientific endeavour.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating 'sulfate' as 'серный' (sulphuric). The correct term is 'сульфат'.
- Do not confuse with 'радиоактивные осадки' (radioactive fallout).
Common Mistakes
- Misspelling as 'radium sulphide' (a different compound).
- Mispronouncing 'radium' as /ˈrædiəm/ instead of /ˈreɪdiəm/.
- Using it as a general term for anything radioactive.
Practice
Quiz
In which field was radium sulfate most historically significant?
FAQ
Frequently Asked Questions
No, its medical and industrial use has been completely abandoned due to the extreme health risks associated with radium's radioactivity. Safer artificial radioisotopes have replaced it.
It is a white crystalline solid. Its historical luminous paints glowed due to the radiation exciting a phosphorescent zinc sulfide base, not because the compound itself was coloured.
'Sulfate' is the standard International Union of Pure and Applied Chemistry (IUPAC) spelling. 'Sulphate' is a traditional British English variant. American English uses only 'sulfate'.
It is extremely hazardous. Direct contact poses a severe risk of radiation burns and internal contamination, which can lead to cancer. Historical handling without protection caused many tragedies.