atomic

atomic — adjective

1. describing the very small particles called atoms, or the way these particles beh

1.adjectiveB2
Definition

describing the very small particles called atoms, or the way these particles behave, combine, or are studied.

Example

Dr. Hana studies the atomic structure of carbon in her lab.

atomic + structure (collocation in science contexts)

The textbook shows the atomic mass of every element on the periodic table.

atomic mass / atomic number / atomic weight

Common collocations
  • atomic structure
  • atomic mass
  • atomic number
  • atomic particles
  • atomic level
Synonyms
  • subatomic

    narrower — only for parts smaller than a whole atom

  • molecular

    about whole molecules, not single atoms

Grammar Patterns

atomic + noun

Usage Note

Almost always sits before a noun (atomic structure, atomic mass, atomic particles). Rarely used after a linking verb such as 'be'.

Common Mistakes

The structure is atomic.
The structure is at the atomic level.
'atomic' usually goes before a noun, not after 'be'.

2. powered by, or built to release, the huge energy given off after splitting a sin

2.adjectiveB2
Definition

powered by, or built to release, the huge energy given off after splitting a single atom, especially in weapons or power stations.

Example

The atomic bomb dropped on Hiroshima killed tens of thousands of people.

atomic bomb (fixed compound)

France gets most of its electricity from atomic power stations.

atomic power / atomic energy

Common collocations
  • atomic bomb
  • atomic energy
  • atomic power
  • atomic weapon
  • atomic reactor
  • atomic war
Synonyms
  • nuclear

    the modern, neutral term for the same idea

  • thermonuclear

    stronger — refers to fusion-based bombs

Antonyms

Grammar Patterns

atomic + noun (bomb / power / weapon / energy)

Usage Note

Mostly fixed compounds: atomic bomb, atomic energy, atomic power, atomic weapon, atomic reactor. In neutral technical writing, 'nuclear' is now more common; 'atomic' often carries Cold-War or weapons overtones.

Common Mistakes

The lamp uses atomic energy from a battery.
The lamp uses electricity from a battery.
'atomic energy' means power from splitting atoms, not ordinary electricity.

3. so tiny or basic that it cannot be broken down into smaller parts; used about a

3.adjectiveC1
Definition

so tiny or basic that it cannot be broken down into smaller parts; used about a unit of information, work, or matter that must be handled as a single whole.

Example

In computer science, an atomic action either fully finishes or does not happen at all.

atomic action (technical sense, all-or-nothing)

The teacher broke the lesson into atomic steps that small children could follow.

atomic + steps (extended size sense)

Common collocations
  • atomic action
  • atomic unit
  • atomic step
  • atomic operation
Synonyms
  • indivisible

    plain word for 'cannot be split'

  • elementary

    the most basic kind, with nothing simpler beneath

  • minute

    stresses extremely small size, not indivisibility

Antonyms

Grammar Patterns

atomic + noun (unit / piece / level)

Usage Note

Mostly found in technical writing about computing, databases, and physics, where it stresses that a thing cannot be split. Outside those fields it sounds bookish or metaphorical.

Common Mistakes

Hiro is atomic in size.
Hiro is tiny.
for ordinary 'small', use 'tiny' or 'minute'; 'atomic' suggests something that cannot be divided further.

Word family

  • atom
    nounB2
  • atomically
    adverbC2
  • subatomic
    adjectiveC1

Synonym discussion

Sense: adjective/2

All three describe energy or weapons that come from changes inside an atom, but they sit at different levels of formality and precision. 'Atomic' is the older, more general word; today it sounds slightly Cold-War flavoured and clings to fixed compounds like 'atomic bomb' and 'atomic energy'. 'Nuclear' is now the standard neutral term in physics, policy, and news writing — scientists talk about nuclear reactors, nuclear medicine, and nuclear waste rather than atomic ones. 'Thermonuclear' is the narrowest: it refers only to weapons or reactions that use fusion at very high temperatures, such as the hydrogen bomb. So a journalist might write 'the country tested a thermonuclear device', a textbook would say 'nuclear power station', while history books still speak of 'the atomic age'.

atomic ↗nuclear ↗thermonuclear

Common collocations

Nouns

Phrases

  • the atomic age
  • at the atomic level

Etymology

GreekLatinFrenchEnglish

Built from the noun 'atom' (from Greek 'atomos', meaning 'uncuttable') plus the adjective ending '-ic'. English speakers used it from the seventeenth century to mean 'relating to atoms', and after the first nuclear weapons in 1945 the word picked up its modern meaning of 'using the energy released when an atom splits'.