# Millimole Day is Thursday, October 20 this year

When Mole Day falls on a non-school day, as it does this year, I celebrate Millimole Day. A mole is 6.02 x 1023 things. A millimole is 6.02 x 1020 things. So you celebrate on October 20, which this year falls on a Thursday. You can do all the usual things you do on Mole Day, but with “milli” attached to it. It also opens up new avenues, such as crowning a “Milli” Mole for the day and featuring millimoles — the rodent kind — in skirts and finery (please excuse the drift towards gender stereotyping!). If you happen to have a Millicent in your class, you might involve her in a special way.

Focussing on millimoles, you note that millimoles per litre are the preferred units in many aspects of medicine, at least in Canada. Reports from medical labs present glucose, sodium, potassium, chloride and the various forms of cholesterol in mmol/L. You could have your students look up the “normal” levels of these various components. My most recent blood work report gives these normal levels, all in mmol/L:

1.   glucose, 3.6-6.0

2.    sodium, 135-147

3.   potassium, 3.5-5.5

4.   chloride, 100-110

5.   cholesterol normal levels vary with age to some extent

Or you could use different fractions or multiples of the mole. Micromole Day falls on October 17, a Monday this year. Kilomole Day falls on Wednesday, October 26. Ask your students to come up with all the other possibilities using as many sub-multiples and multiples of the mole as fall within the month of October. They might learn the lesser known prefixes, such as femto, atto, zepto and yocto! Mind you, Yoctomole Day won’t work because a yoctomole is only 0.602 thing, and you can’t have a fraction of a thing.

If you would prefer to celebrate mole day in a month other than October, try converting 6.02 x 1023 into the equivalent number in base 6 (for June) or base 11 (for November). If I have done it right the equivalent to
6.02 x 1023 in base 11 is 7.40 x 1122, which allows for a celebration on November 22, a Tuesday this year. Certainly, celebrating between 7:40 am and 7:40 pm is much more civilized than having to get up at 6:02 am in October to celebrate the tradition.