When converting from moles to atoms/molecules, use Avogadro's number, which is actually x and when converting from moles to grams, use the molar mass in grams per mole, not the atomic mass in atomic mass units.
Human Body Ingredients via imaginaryfoundation: 'The average human has approximately 100 trillion cells and each cell is made of approximately 100 trillion atoms, each of which were originally created in the center of a star.' Here it is by mass: http:/
This really doesn't have much to do with ELL's, but it could be a language-free way to illustrate the positive charge of a cation and the negative charge of an anion, through pictures. I just thought it was adorable.