Happy Mole Day!

It’s mole day. The mole day site is down (try it later), but you can find out about it on Wikipedia.

Mole Day is an unofficial holiday celebrated among chemists in North America on October 23, between 6:02 AM and 6:02 PM[1], making the date 6:02 10/23 in the American style of writing dates. The time and date are derived from the Avogadro constant, which is approximately 6.02×1023, defining the number of particles (atoms or molecules) in a mole, one of the seven base SI units.

Mole Day originated in an article in The Science Teacher in the early 1980s.[2] Inspired by this article, Maurice Oehler, now a retired high school chemistry teacher from Prairie du Chien, Wisconsin, founded the National Mole Day Foundation (NMDF) on May 15, 1991.[2]


  1. #1 rob
    October 23, 2009

    on Pi day, (march 14th) people celebrate by eating pie.

    what do the eat on mole day???!!?

  2. #2 the bug guy
    October 23, 2009
  3. #3 NewEnglandBob
    October 23, 2009

    I like Avagadro on salad.
    Especially when it is made into Guacamole.

  4. #4 Greg Laden
    October 23, 2009

    You don’t eat. YOu drik 18 oz of water. Or grams. Or whatever. I could never do moles in my head.

  5. #5 Jackal
    October 23, 2009

    Oh my Avogadro! I almost forgot to celebrate Mole Day!

  6. #6 noel
    October 23, 2009

    How about 342 grams of sugar?
    I’m giving a quiz today on mole conversions. It’s totally coincidental. I’m sure my students would prefer celebrating some other way.
    Avogadro – guacamole is funny. I never thought of that (the guaca-mole part).

  7. #7 Greg Laden
    October 23, 2009

    A guacamole is one tenth of a mole, right?

  8. #8 Greg Laden
    October 23, 2009

    Q: Why was there only one Avogadro?

    A: When they made him, they broke the Moled

  9. #9 Art
    October 23, 2009

    Play Whack-a-Mole?

  10. #10 Ted Powell
    October 23, 2009

    1023 ==> 10²³

  11. #11 Rick Pikul
    October 23, 2009

    A ‘guaca-mole’ is the amount of guacamole you can make from a mole of avocados.