Naturally occurring copper is composed of 69.17% of 63cu, with an atomic mass of 62.9296 u, and 30.83% of 65cu, with an atomic mass of 64.9278 u. calculate the average atomic mass of copper. g

             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