Question

From naturally occurring isotopes of copper with 63 atomic mass accounts for 69.09% and 65 atomic mass copper accounts for 30.91%. What is the relative atomic mass of copper?

Answer 1

To calculate the relative atomic mass of copper, you need to consider the atomic masses and abundances of its isotopes. Let's perform the calculation based on the given information.

Given:

• Isotope 63Cu: abundance = 69.09%, atomic mass = 63
• Isotope 65Cu: abundance = 30.91%, atomic mass = 65

To find the relative atomic mass (Ar) of copper, we can use the formula:

Ar = (abundance1 * atomic mass1) + (abundance2 * atomic mass2) + ...

Plugging in the values:

Ar = (0.6909 * 63) + (0.3091 * 65) = 43.5507 + 20.07915 = 63.62985

Therefore, the relative atomic mass of copper (Cu) is approximately 63.63.