To calculate the relative atomic mass of element Z, we need to consider the mass of each isotope and its abundance.
The atomic mass of an isotope is determined by the number of protons and neutrons in its nucleus. Here are the atomic masses of the two isotopes in element Z:
- Isotope 85Z: Atomic mass = 85
- Isotope 87Z: Atomic mass = 87
The abundance of each isotope is given as percentages:
- Isotope 85Z: Abundance = 75%
- Isotope 87Z: Abundance = 25%
To calculate the relative atomic mass, we multiply the atomic mass of each isotope by its abundance and sum them up:
Relative atomic mass of element Z = (85 × 0.75) + (87 × 0.25)
Calculating this expression gives us:
Relative atomic mass of element Z = 63.75 + 21.75 = 85.5
Therefore, the relative atomic mass of element Z is 85.5.