Fact #39
July 15, 2026A Single Drop of Water Contains More Molecules Than There Are Stars in the Observable Universe
A tiny drop of water holds an astonishing number of molecules, about 1.5 sextillion trillion. For comparison, astronomers estimate there are around 10 sextillion to 10 septillion stars in the observable universe. Even something as ordinary as a drop of water contains an almost unimaginably large number of molecules, highlighting just how small atoms and molecules really are.
Mini Facts
1
Water molecules are constantly moving, even in a glass of still water.
2
Molecules are so tiny that millions could fit across the width of a single human hair.
3
A single water molecule is made of 2 hydrogen atoms and 1 oxygen atom. (H2O).
4
One mole of any substance contains exactly 6.02214076 x 10(23rd power) particles, known as Avogadro's constant.