this post was submitted on 28 Jan 2026
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xkcd #3200: Chemical Formula

Title text:

Some of the atoms in the molecule are very weakly bound.

Transcript:

Transcript will show once it’s been added to explainxkcd.com

Source: https://xkcd.com/3200/

explainxkcd for #3200

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[–] stelelor@lemmy.ca 18 points 20 hours ago (3 children)

The formula starts with CH, which means the universe is organic.

[–] NachBarcelona@piefed.social 4 points 12 hours ago
[–] PumpkinSkink@lemmy.world 4 points 18 hours ago (1 children)

I mean... there's a C-H bond in there somewhere.

[–] ranzispa@mander.xyz 2 points 3 hours ago

Pretty sure that yes, somewhere in the universe there is organic matter.

[–] djehuti@programming.dev 2 points 16 hours ago

Indeed! Hello!

[–] AnarchoEngineer@lemmy.dbzer0.com 13 points 19 hours ago

I’m not a physicist, but even if Astatine is being produced in minute quantities by decay, a half life of 8hrs should probably put it lower on the numbers than Americium.

Americium is produced anywhere you have lots of free neutrons. This may be rare on earth outside of nuclear power plants and bomb test sites, but not necessarily rare in the universe. Especially since it has a half life of 432years, so unlike astatine it can actually accumulate a bit and not just decay immediately.

Astatine basically doesn’t exist. The total amount in the entirety of earth’s crust at any given time is estimated to be less than a gram.

So I feel like the amounts should be flipped or at the very least closer in orders of magnitude.

[–] GreatRam@lemmy.world 3 points 14 hours ago

Gold and silver are nice

[–] palordrolap@fedia.io 14 points 23 hours ago (5 children)

There are exotic atoms in that chemical formula that aren't in the periodic table. Not even if you count the equivalent table of potential antimatter atoms.

Muonium is sure to exist in non-zero quantities at any one time, for example.

[–] Pyro@programming.dev 12 points 21 hours ago (1 children)
[–] fruitycoder@sh.itjust.works 1 points 2 minutes ago

This made me laugh too much

[–] WR5@lemmy.world 4 points 16 hours ago* (last edited 16 hours ago)

"Approximate chemical formula"

[–] kopasz7@sh.itjust.works 2 points 20 hours ago (1 children)

Still can't find blackholium, what element number is it?

[–] Trail@lemmy.world 2 points 14 hours ago (2 children)
[–] palordrolap@fedia.io 2 points 8 hours ago (1 children)

-1 would be antihydrogen. Blackholium is whatever number is large enough to cause gravitational collapse, so probably one or two more than the largest neutron star.

[–] Trail@lemmy.world 1 points 1 hour ago

Yeah I was more like referring to an overflow or something.

[–] ElBarto@piefed.social 1 points 9 hours ago
[–] gegil@sopuli.xyz 1 points 21 hours ago

What about elements beyond 119?

[–] nialv7@lemmy.world 1 points 22 hours ago

And neutron stars.

[–] humanspiral@lemmy.ca 2 points 18 hours ago (1 children)

surprised there's so much gold.

[–] ryannathans@aussie.zone 2 points 15 hours ago

Neutron stars go brrr