Today, we measured the masses of five different kinds of beans in groups of 50 each, so that we could compare them to the use of the mole in chemistry. So, similar to the mole, we used the unit of “pots”, which were used to count certain amounts of beans that we had.
From the smallest mass in the lab (lentils), we calculated “relative masses”–the masses of each sample of beans divided by the mass of the lentils. This step was included mostly because lentils were used as single “units” and it would show us how many “units” of mass each sample weighed, which would make it easier to solve for the number of beans we would calculate from each sample’s relative mass. The relative masses would also function like molar masses (how many grams per mole of substance), except they would show the masses of one “Pot” of a type of bean. And for every type of bean except Lima, I personally calculated 20 beans per pot, while Lima beans numbered 22 per pot.
The pot is a model for a mole because, like the mole, we can now use it to determine the mass or number of beans in any particular amount or mass of beans. For example, if we had 250 grams of lentils and wanted the number of beans, we could use its “molar mass” of 20 beans per gram, multiplied by 250 grams, to get 5,000 beans. If we had 5 pots of kidney beans, we could use its mass of 9.904g per pot times 5 pots to get 49.52 grams, etc.
And just like how we used relative masses with the beans, chemists use relative masses, calculated by dividing the atomic mass of an element by the mass of one hydrogen atom, which is, like lentils, the element with the smallest mass. I mean, it’s technically divided by 1/12th the mass of a carbon-12 atom, probably because that isotope of carbon is the most abundant and carbon is “so super important” that we had to find some use for it as a standard, but the mass of that 1/12th is essentially 1 amu, which is hydrogen’s mass anyways. And for reading this far, here’s another picture.