63.5456 amu
Data Given:
Atomic Mass of ⁶³Cu = 62.9296 amu
Natural Abundance of ⁶³Cu = 69.17 %
Atomic Mass of ⁶⁵Cu = 64.9278 amu
Natural Abundance of ⁶⁵Cu = 30.83 %
Formula Used:
Average Atomic Mass = [(Atomic Mass of ⁶³Cu × Natural Abundance of ⁶³Cu) + (Atomic Mass of ⁶⁵Cu × Natural Abundance of ⁶⁵Cu)] ÷ 100
Putting values,
Average Atomic Mass = [(62.9296 × 69.17) + (64.9278 × 30.83)] ÷ 100
Average Atomic Mass = [(4352.8404) + (2001.7241)] ÷ 100
Average Atomic Mass = 6354.5645 ÷ 100
Average Atomic Mass = 63.5456 amu