Calculus 1000A/B Lecture Notes - Stoichiometry, Weighted Arithmetic Mean, Atomic Number

• School: Western University
• Department: Calculus
• Course: Calculus 1000A/B
• Professor: Felix Lee

Document Summary

The number of protons (z) in an atom defines the identity of the element and its atomic number. Isotopes have the same number of protons but different number of neutrons, so they have a different mass number (a) The mass on the periodic table for any element is the weighted average of the masses of all the isotopes. All exist, but the periodic table doesn"t have any of them because they take the weighted. Recall that mole is simply a term that describes a certain quantity: 6. 02x1023. Moles = (mass of stuff in grams)/(mass of 1mol of stuff in g mol-1) Molarity (units of m or mol/l) describes the number of moles of material in one litre of solution, so it is a measure of concentration. Molarity = (moles of stuff [mol])/(volume[l]) -> mol/l. Mass percent = (mass of one species)/(total mass of sample) x 100. % of an element in a compound. % of a compound in a mixture.