On November 16, 2018, representatives from more than 50 countries are expected to make history when they gather in Versailles, France, to vote on redefining the

On November 16, 2018, representatives from more than 50 countries are expected to make history when they gather in Versailles, France, to vote on redefining the SI, including the mole. The vote will close the book on this chapter of Vocke and Rabb’s work, but will open a new chapter in chemistry as the fundamental unit, for that branch of science will no longer be tied to a physical object but a constant of nature. Interesting to find out that the concept every chemistry student is taught is about to be redefined. Odd that they couldn't schedule it on mole day... I remember struggling with the concept of the mole in high school. After working many problems I was able to see what the big deal was about: The mole links the macroscopic world we can directly experience with our senses to the atomic world which we cannot. Think of the mole as a monetary exchange rate between these two worlds. It converts mass of a pure sample (which we can measure directly on the bench top) to number of particles (which we can't). Chemistry and accounting have a lot in common. If you're good with money, you should be good at chemistry. Anyone can pick up an ingot of silver, place it on a balance, and read the number to get the mass. Use of the mole (and the atomic weight of silver) allows this measurement to be converted into the number of silver atoms in the sample. This process is identical to the one you'd use to figure out how much your hotel in Paris will cost you in dollars.