Exactly as the title asks.

Pure oxygen is generally represented as O2 yet oxygen is an element of the periodic table. Why is it O2 and not just O?

  • PrunesMakeYouPoop@kbin.social
    link
    fedilink
    arrow-up
    58
    arrow-down
    1
    ·
    1 year ago

    There are 7 elements that will naturally form covalent bonds with themselves.
    Here is how to remember these diatomic elements:

    (H)ave (N)o (F)ear (O)f (I)ce (Cl)old (Br)eer.
    The Ice is solid, the beer is liquid, and everything else is a gas.

    • Fogle@lemmy.ca
      link
      fedilink
      arrow-up
      4
      ·
      1 year ago

      That sounds more complicated than what I’ve remembered. Which is simply hofbrincl

    • xkforce@lemmy.world
      link
      fedilink
      arrow-up
      2
      ·
      edit-2
      1 year ago

      Those are the 7 that form diatomic molecules not the only elements that form covalent bonds with other atoms of that element. The s block excluding hydrogen, d block and f block are all metals and are held together with metallic bonds which are a type of covalent bond. Mercury forms weak, transient metallic bonds in its elemental form but robust bonds in the Hg2(2+) dication. Sulfur, Selenium and Tellurium form rings and chains, the former being typically 8 atoms and the latter being hundreds or thousands of atoms in length. Phosphorus is in the form of P4 molecules in white phosphorus and is a network covalent solid in many of its other allotropes. Eg. black phosphorus is a series of stacked undulating chicken wire sheets. Arsenic and Antimony similarly adopt this undulating chicken wire sheet structure as well. Bismuth, lead, polonium, aluminum, gallium, thallium and tin are all metals held together with metallic bonds. Carbon, silicon and germanium commonly form the cubic diamond structure although carbon is most stable as graphite (stacked chicken wire) and can form molecules like fullerene and nanotubes as well as chains (carbyne). Boron tends to form crystals containing icosahedrons. The only elements that rarely react with other elements let alone form covalent bonds with one another in bench stable compounds are the noble gases: Helium, Neon, Argon, Krypton, Xenon and Oganesson.