atom

The word “atom” means the smallest unit of a chemical element that retains its properties, made up of a nucleus and surrounding electrons. In plain terms, the basic building block of matter — or, informally, the tiniest possible amount of something.

“Atom” is pronounced A-tuhm ([ˈæɾm̩] in IPA).

Here is “atom” used in a sentence: “Every atom of oxygen has eight protons.”

“Atom” is a noun.

The word “atom” comes from Latin. From Latin atomus, from Greek atomos ("indivisible"), from a- ("not") + temno ("to cut"). Ancient philosophers imagined atoms as the smallest possible pieces of matter, though we now know atoms themselves are divisible.

“Atom” is an uncommon word in modern English, usually learned at around the A2 level.

“Atom” has 2 distinct senses listed in this dictionary. The most common is: the smallest unit of a chemical element that retains its properties, made up of a nucleus and surrounding electrons.

An atom is the smallest unit of a chemical element that retains its properties, made up of a nucleus and surrounding electrons, while a molecule forms when two or more atoms bond together. A molecule can therefore consist of atoms from one element or several different elements.

Yes, atom can be used figuratively to mean a tiny or minimal amount of something, as in 'not an atom of truth', extending its scientific sense of smallness to describe negligible quantities in general.

An atom is a complete unit made up of a nucleus and surrounding electrons, while an electron is just one of the smaller particles that orbit within an atom. An electron is therefore a component part of an atom, not a separate whole unit.