Chemistry

$500,000 of Calcium - Periodic Table of Videos
Diabolical daughter is taking a chemistry class so, naturally, or perversely, depending on your point of view, I am also studying chemistry. One of things we've been working on is determining how many grams of a product you can expect from a chemical reaction of two compounds, given the initial amounts. This involves calculating the molecular weight of the compounds, which means looking up the atomic mass in the periodic table. Since the atomic mass of an atom is simply the number of protons plus the number of neutrons (electrons weigh so little that we don't even bother with them) you might think that the atomic weight would be a nice round integer as well. But that discounts the isotopes: all elements come in multiple flavors. Any bunch of atoms one element will have the same number of protons, but they will have different numbers of neutrons, so individual atoms may have different weights. The atomic weight is the weighted (heh) average of the masses of all the known flavors / isotopes.

This business of electromagnetic separation of isotopes of Calcium is similar to the process the U.S.A. used to separate U-235 from the mass of refined Uranium.