Familiar as most people are with the concept of atomic theory, it is exceedingly difficult to comprehend how small such particles really are.
Let's do a thought experiment.
Suppose you have a magic wand. By waving it over a tablespoon of water, say half an ounce or 15 grams, you could increase every water molecule to the size of a marble, half an inch in diameter.
How much volume would the newly enlarged molecules of water occupy?
Go very big. And then increase that by a very large amount. Just guess before scrolling down for the approximate answer.
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Fifteen grams of water molecules expanded to half an inch in diameter would raise ocean levels about a mile. The calculations are muddled by the additional land area currently between sea level and one mile in elevation into which oceans would backfill.
But it's truly a lot. Conversely, molecules are REALLY little.