A 7.36 g sample of copper is contaminated with a additional 0.51 g sample of zinc. suppose an atomic mass measurement was performed on this sample. What would be the measured atomic mass?

64.46

63.67

63.94

65.38

For the answer to the question above, the molar mass of the sample is equal to the summation of the molar mass of the elements multiplied by the abundance of the elements by mole. In this case, copper has an abundance of 93.69 percent while zinc has 6.31 percent. In this case, the average molecular weight is 63.67 g/mol. So the answer is the second one.