The difference between an allegory and a symbol is that an allegory is a complete narrative that conveys abstract ideas to get a point across, while a symbol is a representation of an idea or concept that can have a different meaning throughout a literary work.
Two small aluminum spheres, each of mass 0.0250 kilograms, are separated by 80.0 centimeters. How many electrons does each sphere contain? (The atomic mass of aluminum is 26.982 grams per mole, and its atomic number is 13.) The attempt at a solution I said that there are 6.02*10^23 atoms in a mole, and noted that after converting the mass into grams each sphere has .9265 moles. If the Aluminum spheres are uncharged there are 13 electrons per atom.
A mole is the quantity of anything that has the same number of particles found in 12.000 grams of carbon-12. That number of particles is Avogadro's Number, which is roughly 6.02x10 23. A mole of carbon atoms is 6.02x10 23 carbon atoms. A mole of chemistry teachers is 6.02x10 23 chemistry teachers. It's a lot easier to write the word 'mole' than to write '6.02x10 23 ' anytime you want to refer to a large number of things! Basically, that's why this particular unit was invented.