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> Yes, water is common—in fact, it is the third most common molecule in the universe. What are the first 2 most common molecules? H2 and O2? In another thread
by stephengillie 11y ago
> Yes, water is common—in fact, it is the third most common molecule in the universe.
What are the first 2 most common molecules? H2 and O2?
In another thread on HN this morning, we learned that Hydrogen, Helium, & Oxygen are the 3 most common elements in the universe. To tangent off a different commenter's remark, the 1st and 3rd most common elements in the universe create the 3rd most common molecule.
- marcosdumay 11y agoProbably H2 and He.
- stephengillie 11y agoBut Helium doesn't form into diatomic molecules. The binding energy isn't there.
- crusso 11y agoYou can have a one atom molecule, depending upon which definition you look at.
- deleted 11y ago[deleted]
- burkaman 11y agoI have never seen that definition and I can't find it online anywhere. Wikipedia gives 6 pretty solid looking references for the "two or more atoms" definition.
- bonobo 11y agoThe same Wikipedia page on molecules that says they have "two or more atoms held together" also says this in the next paragraph: In the kinetic theory of gases, the term molecule is often used for any gaseous particle regardless of its composition. According to this definition, noble gas atoms are considered molecules despite being composed of a single non-bonded atom.
- burkaman 11y agoWell, my bad, should have read farther.
- enraged_camel 11y agoThere isn't a single definition of "molecule" that includes fewer than two atoms.
- crusso 11y agoOne google search and I saw two of them, including in Wikipedia.
- Thorondor 11y agoAfter H2, carbon monoxide would be the next most common molecule in interstellar clouds. [1] However, I don't know about the universe as a whole. [1] https://www.cfa.harvard.edu/mmw/history.html https://www.cfa.harvard.edu/mmw/history.html