Conversion of mole to grams k in mole = 1 mole/ atomic mass K in mole =1/ 39.0983 g/mole = 0.255765 g/mole converting 40 grams of K K 40 grams x [ 1 mole/ 39.0983 grams] = 1.0230623 mole There are 1.0230623 moles of K in 40 K of Potassium
Mass number is the number of protons and neutrons in an atom, and it tells us about the mass of the atom in amu, or atomic mass units. Atomic mass is the average mass of all the isotopes of a certain type. It is a weighted average that takes into account the abundances of all of the different isotopes