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An electron weighs so little that about a billion billion billion of them make up one gram.

Physics Facts, sourced to NIST.

What it means

Written out, that is a one followed by twenty seven zeros. The number is hard to feel, so try it the other way around: if you could line up every electron in a single gram and count one a second, you would still be counting long after the sun had burned out. Almost all the mass of ordinary matter sits in the nucleus, and the electrons contribute a rounding error.

The claim comes from NIST, and the page it comes from was read on 2026-08-27 to confirm it still says this.

This is not the kind of claim that goes out of date, which is why it was set as a puzzle rather than a fact with a shelf life.

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This fact is a cryptogram here: 74 letters over 19 different ones, graded medium.

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