One Glass, Thousands of Atoms Drifting Through the World's Oceans
A 250 mL glass of water contains about 2.5 × 10^25 atoms, while all Earth's oceans hold roughly 5.3 × 10^21 glasses of water; thus that glass contains about 4,700 times more atoms than there are ocean glasses. If you marked every atom and mixed it back into the seas, thousands of those marked atoms would eventually appear in any new glass drawn anywhere on Earth, illustrating how unimaginably small atoms are relative to macroscopic objects and why biological molecules require enormous numbers of atoms to behave reliably.
