isomerism
Low (C2/Technical)Formal, Scientific, Academic
Definition
Meaning
The phenomenon whereby two or more chemical compounds have the same molecular formula but different structural arrangements or spatial orientations, resulting in different properties.
In broader scientific and metaphorical contexts, it can refer to any situation where two entities share the same fundamental components but are arranged differently, leading to distinct characteristics or functions.
Linguistics
Semantic Notes
The term is almost exclusively used in chemistry and related scientific fields (e.g., biochemistry, pharmacology). Its metaphorical use is rare and highly specialized.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling is consistent.
Connotations
Purely technical with no regional connotations.
Frequency
Equally low frequency in both academic/scientific contexts.
Vocabulary
Collocations
Grammar
Valency Patterns
The isomerism of [compound]Isomerism results from...[Compound] shows isomerism.Vocabulary
Synonyms
Strong
Weak
Vocabulary
Antonyms
Usage
Context Usage
Business
Virtually never used.
Academic
Core term in chemistry lectures, textbooks, and research papers discussing molecular structure.
Everyday
Extremely rare; would only be used by someone with a chemistry background.
Technical
Essential in chemistry, pharmacology (drug design), and materials science.
Examples
By Part of Speech
noun
British English
- The isomerism observed in these hydrocarbons is fascinating.
- We shall now turn our attention to stereoisomerism.
American English
- The textbook chapter on isomerism is due next week.
- Geometric isomerism is also known as cis-trans isomerism.
Examples
By CEFR Level
- Isomerism is an important concept in organic chemistry.
- The two molecules are examples of isomerism.
- The pharmacological activity of the drug is profoundly affected by its optical isomerism.
- Understanding structural isomerism is crucial for predicting the behaviour of organic compounds.
Learning
Memory Aids
Mnemonic
Imagine identical twin ISOMERs (I-SO-MER) who look the same (same formula) but have different personalities (different properties) due to their internal ISOMERism.
Conceptual Metaphor
TWINS WITH DIFFERENT PERSONALITIES: Same genetic makeup (formula), different traits (properties).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'изомерность' (which is correct) and 'изоморфизм' (isomorphism, a different concept in crystallography).
Common Mistakes
- Misspelling as 'isomirism' or 'isomerrism'.
- Using it to mean 'isomorphism'.
- Using it in non-scientific contexts.
Practice
Quiz
In which field is the term 'isomerism' primarily used?
FAQ
Frequently Asked Questions
Structural isomerism (or constitutional isomerism), where atoms are connected in a different order.
No, isomerism is a property of compounds, specifically molecules with the same molecular formula but different arrangements.
Because different isomers (e.g., enantiomers) of the same compound can have drastically different biological effects, with one being therapeutic and the other potentially harmful.
It is generally used as an uncountable noun (e.g., 'the isomerism of pentane'). However, you can refer to specific 'types of isomerism' (countable).