molecule
C1Formal, Academic, Technical
Definition
Meaning
The smallest physical unit of a chemical element or compound, consisting of two or more atoms held together by chemical bonds.
A minute particle; a tiny amount of something; used metaphorically to describe the smallest component of a complex entity or system.
Linguistics
Semantic Notes
The primary sense is overwhelmingly scientific. The metaphorical use is possible but less common and typically self-conscious or literary. It is a countable noun.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Pronunciation differs slightly (see IPA). Spelling and grammar are identical.
Connotations
Identical, strongly linked to chemistry and physical sciences.
Frequency
Equally frequent in scientific contexts in both varieties. Non-scientific metaphorical use is rare in both.
Vocabulary
Collocations
Grammar
Valency Patterns
molecule of [substance]molecule consisting of [atoms]molecule that/which [clause]Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “Not a molecule of truth (in it): meaning not even the smallest amount of truth.”
Usage
Context Usage
Business
Virtually unused, except in specific industries like pharmaceuticals or materials science (e.g., 'We patented the new molecule').
Academic
Extremely common in chemistry, biochemistry, physics, and materials science papers and textbooks.
Everyday
Rare, mainly in simplified explanations of science (e.g., 'A water molecule has two hydrogen atoms').
Technical
The primary, precise term in all fields of chemistry and molecular biology.
Examples
By Part of Speech
adjective
British English
- The molecular structure was analysed.
- They studied molecular biology.
American English
- The molecular structure was analyzed.
- They studied molecular biology.
Examples
By CEFR Level
- Water is made of tiny molecules.
- A molecule of oxygen gas contains two atoms.
- Scientists can see single molecules with special microscopes.
- The drug's effectiveness depends on the precise shape of its molecule.
- In this reaction, one large molecule splits into two smaller ones.
- The researcher elucidated the molecule's conformational dynamics using NMR spectroscopy.
- Supramolecular chemistry deals with structures composed of multiple molecules held together by non-covalent bonds.
Learning
Memory Aids
Mnemonic
Think of a MOLE (the small animal) in a CUE ball (a pool ball). A tiny 'mole' is the core of the 'cue ball' structure.
Conceptual Metaphor
BUILDING BLOCK / SMALLEST UNIT: Conceptualized as the fundamental, indivisible (in a practical sense) component from which larger structures are built.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- The Russian word 'молекула' is a direct cognate with identical meaning and usage. No trap exists.
Common Mistakes
- Using 'atom' and 'molecule' interchangeably (an atom is a single element; a molecule is a group of atoms).
- Pronouncing it as /moʊˈliːkjuːl/ (incorrect stress).
- Using plural verb forms with 'molecule' as a collective noun (e.g., 'The molecule are...' is wrong).
Practice
Quiz
Which of the following best describes a molecule?
FAQ
Frequently Asked Questions
An atom is the smallest unit of a chemical element (e.g., one iron atom). A molecule is a group of two or more atoms held together by chemical bonds (e.g., O2, H2O, CH4).
No, by definition a molecule requires at least two atoms. Noble gases like helium or argon exist as single atoms, not molecules, in their natural state.
Rarely. It is sometimes used metaphorically to mean 'a tiny amount' (e.g., 'There wasn't a molecule of evidence'), but this is stylised and not common in everyday speech.
The stress is on the first syllable: MOL-e-cule. The common mispronunciation 'mo-LE-cule' (stress on the second syllable) is incorrect.
Collections
Part of a collection
Science and Technology
B1 · 47 words · Basic scientific concepts and modern technology.