molecule
molecule — noun
1. the tiniest piece of a chemical material that still behaves like that material,
the tiniest piece of a chemical material that still behaves like that material, made when several atoms become linked by chemical bonds
A water molecule has two hydrogen atoms and one oxygen atom bonded together.
pattern: a [substance] molecule + has/consists of
Selim's teacher drew a diagram showing how each salt molecule forms a repeating pattern.
pattern: each + [substance] + molecule
When sugar dissolves in water, each molecule separates and spreads out evenly.
Élise learned how a DNA molecule stores the instructions for making proteins in the body.
The oxygen molecule that animals breathe is formed when two oxygen atoms join tightly together.
- compound
a specific type of molecule made of two or more different elements joined together, whereas molecule can refer to any bonded group of atoms
文法句型
a molecule of [substance]
[substance] molecule
用法筆記
In technical chemistry, a single atom of a noble gas (such as helium) is not considered a molecule — molecules always involve two or more atoms bonded together.
常見錯誤
2. a very small piece or amount of a substance, especially when you want to emphasi
a very small piece or amount of a substance, especially when you want to emphasize that there is extremely little or none at all
The technician wiped the lens until not a molecule of dust remained on the surface.
negative construction: not a molecule of [substance]
Hoa noticed tiny molecules of grease floating on the surface of the soup.
non-technical use with everyday material
After scrubbing the pan for twenty minutes, every molecule of burnt food was finally gone.
Valentina checked the table for any molecule of sand left after sweeping the floor.
Eve scraped every molecule of old paint off the door before painting it again.
- particle
a more general word for any tiny piece of matter; does not carry the chemical meaning of two or more bonded atoms
- speck
even smaller and more informal than molecule in this sense; typically used for visible tiny bits (e.g., a speck of dust)
- bit
the most everyday word; less precise but natural in conversation
文法句型
not a molecule of [substance]
a molecule of [substance/material]
用法筆記
This sense is non-technical and informal. It is different from sense 1 because it does not refer to a specific chemical structure — it simply means a very tiny bit of something. It appears often in negative statements for extra emphasis.