atom
C1Formal (technical/scientific); Neutral (figurative use)
Definition
Meaning
The smallest unit of a chemical element, consisting of a nucleus of protons and neutrons with electrons orbiting around it.
1. An extremely small amount or quantity of something. 2. The fundamental or irreducible constituent of a system or concept.
Linguistics
Semantic Notes
In technical contexts, 'atom' refers precisely to the physical particle. In figurative use, it emphasizes extreme smallness or indivisibility (e.g., 'not an atom of truth'). The plural 'atoms' can refer to tiny particles more generally in older or literary usage.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Pronunciation differs slightly (see IPA).
Connotations
Identical connotations in both varieties.
Frequency
Slightly more frequent in American academic/scientific publishing due to larger output, but this is negligible for learners.
Vocabulary
Collocations
Grammar
Valency Patterns
[adjective] + atom (e.g., unstable atom)atom + of + [noun] (e.g., atom of hydrogen)[verb] + the atom (e.g., split the atom)Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “not an atom of (e.g., not an atom of sense)”
- “to split the atom”
- “the power of the atom”
Usage
Context Usage
Business
Rare. Possibly in 'atom of doubt' or in tech company names/metaphors for disruptive innovation.
Academic
Very common in physics, chemistry, and related sciences. Core technical term.
Everyday
Common in figurative expressions ('not an atom of truth') and historical discussions (atom bomb).
Technical
The primary, precise term in physics and chemistry for the basic unit of an element.
Examples
By Part of Speech
verb
British English
- (Rare/obsolete) To reduce to atoms.
American English
- (Rare/obsolete) To atomise.
adverb
British English
- (No standard adverbial form)
American English
- (No standard adverbial form)
adjective
British English
- The atom bomb changed history.
- They discussed atomic theory.
American English
- The atomic age began in 1945.
- Atomic structure is complex.
Examples
By CEFR Level
- Water is made from tiny atoms.
- The scientist looked at an atom.
- An atom is too small to see without special tools.
- The book explained how atoms join together.
- The researchers succeeded in splitting the atom, releasing enormous energy.
- There isn't an atom of evidence to support his bizarre theory.
- Quantum mechanics describes the counterintuitive behaviour of particles at the atomic level.
- The treaty aimed to prevent the proliferation of atomic weapons.
Learning
Memory Aids
Mnemonic
Imagine A Tiny Orange Mouse (A-TOM). The mouse is the smallest thing you can imagine, just like an atom.
Conceptual Metaphor
BUILDING BLOCK (Atoms are the building blocks of matter). / SEED (The atom contains the potential for great power or growth).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'атом' (same meaning). The trap is in figurative use: Russian might use 'капля' (drop) or 'крошка' (crumb) where English uses 'atom' (e.g., 'not an atom of evidence' = 'ни капли доказательств').
Common Mistakes
- Using 'atom' to mean 'molecule' (e.g., 'a water atom' is incorrect; it's a water *molecule*).
- Misspelling as 'attom' or 'atome'.
- Incorrect pluralisation ('atoms' is correct).
Practice
Quiz
In the sentence 'She didn't have an atom of patience left,' the word 'atom' is used:
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 bonded together (e.g., a water molecule, H2O).
Yes, it is commonly used figuratively to mean 'the smallest possible amount' (e.g., 'not an atom of truth in it').
Yes, 'atomic' is the standard adjective (e.g., atomic weight, atomic energy). The rarely used verb 'atomize' means to reduce to atoms or fine particles.
While the word itself is known earlier, its precise technical usage and common figurative applications are typically mastered at an advanced level, requiring nuanced understanding.