brownian motion
Pronunciation
Noun
B2 Upper-intermediate
Quick answer
The random, jittery movement of small particles suspended in a liquid or gas, caused by collisions with surrounding molecules.
Usage notes
Brownian motion was one of the key pieces of evidence that convinced scientists atoms and molecules really exist.
Test yourself
Which word fits the gap? "Under the microscope, the pollen grains showed the constant, erratic jiggling of _____."
Answer: brownian motion
In your own words, what does "brownian motion" mean?
The random, jittery movement of small particles suspended in a liquid or gas, caused by collisions with surrounding molecules.
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