[Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/dictionaries/school/w/molecule.html)

[home](https://md.mova.elamur.ai/free/en/) / [dictionaries](https://md.mova.elamur.ai/free/en/dictionaries/) / [The school dictionary](https://md.mova.elamur.ai/free/en/dictionaries/school/) / molecule

[← M](https://md.mova.elamur.ai/free/en/dictionaries/school/M/)

# molecule

«molecule» in Mova's school dictionary: **the smallest unit of a substance that still has its…** — its meaning for a pupil, its sense in the lessons and examples, with 5 sentences of Mova's corpora that use it.

### part of speech

noun (a molecule, molecules)

### meaning for a pupil

1) A molecule is the smallest unit of a substance that still has its properties, made of two or more atoms joined together. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#m1)

2) A water molecule, for example, is two hydrogen atoms joined to one oxygen atom (H2O). [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#m2)

### sense in the lessons

In science lessons molecules come up in states of matter: in solids molecules are packed tightly and vibrate, in liquids they slide past each other, in gases they move fast and far apart; heating makes them move faster. Pupils learn formulas like H2O (water), CO2 (carbon dioxide) and O2 (oxygen). Molecules are much too small to see, even with an ordinary microscope.

### examples

- A water molecule has three atoms. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#x1)
- When ice melts, its molecules start to move more freely. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#x2)
- Oxygen gas is made of molecules with two oxygen atoms. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#x3)
- Smells reach your nose as tiny molecules floating in the air. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#x4)
- Heating makes molecules move faster. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#x5)
- Carbon dioxide molecules are breathed out by animals. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#x6)
- A single drop of water has more molecules than there are stars we can see. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/#x7)

### note

Plural «molecules». Say «MOL-ih-kyool». Adjective «molecular». An atom is a single particle of an element; a molecule is atoms joined together. Not all substances are made of molecules (metals and salt are made differently), but at primary level «particles» is often used for all of them.

### In the corpora

- [Atoms rarely stay alone: they join up into groups called molecules, a bit like Lego bricks clicking together.](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/3-molecules-when-atoms-join-up/0/)
- ["H2O" means two hydrogen atoms joined to one oxygen atom: that is one molecule of water.](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/3-molecules-when-atoms-join-up/1/)
- [Our noses sense particular molecules; natural gas has no smell, so companies add a smelly chemical to make leaks noticeable.](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/3-molecules-when-atoms-join-up/13/)
- [Carbon atoms can link into long chains and rings, which is how huge molecules like sugar, wood and DNA are built.](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/3-molecules-when-atoms-join-up/19/)
- [Melting, freezing, boiling and condensing are reversible changes, because the molecules stay the same.](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/9-changes-you-can-and-cannot-undo/5/)

### Trees and pragmatics

[Every meaning and example of «molecule» parsed by Mova](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/M/molecule/), each sentence with its dependency tree and frames.