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Continuing my experimentation with bismuth

  1. Jul 30, 2015 #1
    The more i study this strange element, the more interesting it becomes.

    I found that bismuth only shows it's colorful oxides when exposed to air while hot/molten.

    I decided to go outside and polish the sample using an abrasive liquid known in Brazil as "Saponáceo Cremoso".
    Don't know what it's called in english-speaking countries.

    Edit: It's called "Scouring cream" in english.

    Anyway, it's used to polish aluminum cookware as well as any other metal surfaces.

    So i took my bismuth sample out and started polishing.

    The metal finally showed it's natural appearance: A lustrous, shiny and silvery material that resembles lead or iron.

    But something more happened: It didn't oxidize. Even after being exposed to air, water or even the oils from my hand, it's still shiny, without any noticeable color change.

    But when molten, it tarnishes instantaneously!

    Anyone knows why?
     
  2. jcsd
  3. Jul 30, 2015 #2

    Borek

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    Staff: Mentor

  4. Jul 30, 2015 #3
  5. Jul 30, 2015 #4

    Borek

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    Staff: Mentor

    No. Catalyst is a catalyst, heat is a heat. Both speed up the reaction, but for completely different reasons.
     
  6. Jul 30, 2015 #5
    Oh, nice. Thank you for clarifying :smile:.
     
  7. Jul 31, 2015 #6

    DrDu

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    As you were melting Bismuth and already messing up one pan: Did you observe the solid bismuth to float on the melt? Bismuth is one of the few substances (like water) where the solid is less dense than the melt.
     
  8. Jul 31, 2015 #7
    Yes, i did!
    While the bismuth was molten, there was a small chunk floating on the top of the liquid.

    I won't do it on the kitchen again. One pan just went to the trash because of this hehe. :biggrin:
     
  9. Jul 31, 2015 #8

    DrDu

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    Bismuth is also a relatively strongly diamagnetic substance, i.e. it gets repelled by a magnetic field. If you mount your probe on a string and bring a strong magnet close (best one of these small neodymium magnets) it will turn away.
     
  10. Jul 31, 2015 #9
    Cool experiment too! I tried it with some magnets from old hard drives.

    Bismuth diamagnetism is very weak.
    But still stronger than any other material i have ever seen.
     
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