To calculate the relative atomic mass of element Z, we need to take into account the mass of each isotope and its respective abundance.
Given:
- Isotope 1: mass number = 57, abundance = 75%
- Isotope 2: mass number = 59, abundance = 25%
To find the relative atomic mass, we'll multiply the mass of each isotope by its abundance and then sum up the results:
(57 * 0.75) + (59 * 0.25) = 42.75 + 14.75 = 57.5
Therefore, the relative atomic mass of element Z is 57.5.