Calculate the average atomic mass of an element containing 39.9% of atoms with a mass of 69 amu and 60.1% of atoms with a mass of 71 amu. Show your work for credit and round your answer to one decimal place.

Calculate the average atomic mass of an element containing 399 of atoms with a mass of 69 amu and 601 of atoms with a mass of 71 amu Show your work for credit a class=