As the unit of measurement for the amount of substance—proportional to the elementary entities (atoms, 
molecules, ions or other particles) within a volume, a way of bundling masses of into a magnitude of quantity after the conventions of a teaspoon, a dozen, a baker’s dozen or a gross so that chemical reactions, scientists can accurately express the concentration—recipe—of reactants. Despite the different natures, a mole of water (a chemical compound) and a mole of mercury (an element) have the same number of discrete particles in them—which is Avogadros’ Number, 6,022 ๏ฝ 10²³ mol, six hundred two sextillion, two hundred quintillion. It’s useful to have such a normalising proxy for grasping the number of atoms in a given object. Enthusiasts and educators celebrate Mole Day on this day (US calendar conventions) from 06:02 in the morning until two after six in the evening as a way to drum up interest in chemistry and scientific literacy.
one year ago: visiting Crete
two years ago: your daily demon: Sabnok plus assorted links to revisit
three years ago: circuit judge Roy Cohn, a pretend Communist coup, more links to enjoy, the beginning of the world plus an appreciation of the colour russet
four years ago: more links worth revisiting plus more on the far future night sky
five years ago: the canals of Mars, swing sixties cover of Red Hot Chili Peppers, the first Russian rapper plus noteworthy files from the US National Records Archive
