Question Detail
Question
If naturally occurring copper consists of 69.2% copper-63 (⁶³Cu) and 30.8% copper-65 (⁶⁵Cu) calculate the relative atomic mass of Cu
Correct Answer
Option C is the correct answer.
Detailed Explanation
Average atomic mass = (0.692 × 63) + (0.308 × 65) = 43.596 + 20.02 = 63.616 ≈ 63.6.
Hint
Multiply the mass of each isotope by its fractional abundance and sum the results.