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atom

[ at-uhm ]

Phonetic (Standard)IPA

noun

Physics.
1. the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical attraction; the number of protons determines the identity of the element.
2. an atom with one of the electrons replaced by some other particle:
  muonic atom;
  kaonic atom.
Energy. this component as the source of nuclear energy.
a hypothetical particle of matter so minute as to admit of no division.
anything extremely small; a minute quantity.
Synonyms: , , , , ,

atom

/ ˈæ��ə�� /

noun

1. the smallest quantity of an element that can take part in a chemical reaction
2. this entity as a source of nuclear energy See also atomic structure
  the power of the atom
any entity regarded as the indivisible building block of a theory
the hypothetical indivisible particle of matter postulated by certain ancient philosophers as the fundamental constituent of matter See also atomism
a very small amount or quantity; minute fragment
to smash something to atoms
there is not an atom of truth in his allegations

atom

The smallest unit of an element, consisting of at least one proton and (for all elements except hydrogen) one or more neutrons in a dense central nucleus, surrounded by one or more shells of electrons. In electrically neutral atoms, the number of protons equals the number of electrons. Atoms remain intact in chemical reactions except for the removal, transfer, or exchange of certain electrons.
Compare compoundSee also ion

atom

A unit of matter ; the smallest unit of a chemical element . Each atom consists of a nucleus , which has a positive charge , and a set of electrons that move around the nucleus. ( See Bohr atom .)

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Notes

Atoms link together to form molecules .

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Word History and Origins

Origin of atom¹

First recorded in 1350–1400; Middle English attomos, athomus, from Latin atomus, from Greek á�ٴǳ��ǲ�, noun use of á�ٴǳ��ǲ� “undivided,” equivalent to a- a- ⁶ + �ٴǳ�ó�� “divided,” from ��é��Ա𾱲� “to cut”

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Word History and Origins

Origin of atom¹

C16: via Old French and Latin, from Greek atomos (n), from atomos (adj) that cannot be divided, from a- ¹+ temnein to cut

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Example Sentences

Examples have not been reviewed.

These emission lines can split into several components in the presence of a magnetic field, caused by the interaction between the internal magnetic moments of the emitting atoms and molecules with the external magnetic field.

From

In comparison, the most environmentally friendly fuels like e-kerosene and ammonia are created from initially splitting water atoms to obtain hydrogen, which is a very energy-intensive and costly process.

From

But its execution is fiendishly difficult: to harness the power of the atom, develop a new type of clock, and even change the way we measure time itself – all within a few years.

From

It all comes down to ferrihydrite, a poorly crystalline mineral, or a substance where the atoms or molecules are not arranged in well-defined and repeating patterns.

From

Electricity is then used to split the water molecules, freeing up hydrogen atoms.

From

atoll atom-bomb

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