Atom - Definition, Meaning & Synonyms

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SKIP TO CONTENT atom /ˈædəm/ /ˈætəm/ IPA guide

Other forms: atoms

An atom is the basic unit of an element. When you see the chemical formula for water, H2O, it's telling you that each molecule of water is made up of two atoms of hydrogen and one atom of oxygen.

In science class, you've probably come across atoms, the bits that make up molecules. Less scientifically, the word atom can also mean a very small piece of anything at all. The Greek root of atom is atomos, which means "indivisible," since the scientists who first gave the atom its name imagined it couldn't be split or divided into smaller pieces. Even though we know there are smaller things that make up an atom (protons, neutrons and electrons), it's still a good way to think about the word atom.

Definitions of atom

noun (physics and chemistry) the smallest component of an element having the chemical properties of the element see moresee less types: show 8 types... hide 8 types... isotope one of two or more atoms with the same atomic number but with different numbers of neutrons monad (chemistry) an atom having a valence of one carbon atom an atom of carbon hydrogen atom an atom of hydrogen free radical, radical an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule radioisotope a radioactive isotope of an element; produced either naturally or artificially acid hydrogen, acidic hydrogen a hydrogen atom in an acid that forms a positive ion when the acid dissociates deuterium, heavy hydrogen an isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen) type of: substance the real physical matter of which a person or thing consists
noun (nontechnical usage) a tiny piece of anything synonyms: corpuscle, molecule, mote, particle, speck see moresee less types: show 7 types... hide 7 types... grain a relatively small granular particle of a substance grinding material resulting from the process of grinding chylomicron a microscopic particle of triglycerides produced in the intestines during digestion; in the bloodstream they release their fatty acids into the blood flyspeck a tiny dark speck made by the excrement of a fly identification particle a tiny particle of material that can be added to a product to indicate the source of manufacture granule a tiny grain Microtaggant (trademark) a microscopic and traceable identification particle used to trace explosives or other hazardous materials or to prevent counterfeiting type of: material, stuff the tangible substance that goes into the makeup of a physical object

Pronunciation US /ˈædəm/ UK /ˈætəm/ Cite this entry Style: MLA

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Vocabulary lists containing atom

Quantum of Vocabulary: the Parlance of Particle Physics

Even though atoms and their component parts are incredibly tiny, it's impossible to understand the biggest things in the universe —stars, nebulas, and galaxies — without knowing how these invisible particles behave and interact. Up and atom!

Word Generation Science - Introductory Chemistry Concepts

Word Generation Science is a program combining vocabulary with a multidisciplinary discussion of various science topics. Here are links to the word lists for Word Generation Science: Scientific Thinking, Preparing a Scientific Investigation, Measurement, Life Science, Energy, Introductory Chemistry Concepts.

Matter and Energy 1: Atoms and Molecules MORE VOCABULARY LISTS 2 million people are mastering new words. Master a word

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