Answer:
Average Atomic Mass = 10.81
Step-by-step explanation:
Data Given:
Atomic Mass of ¹⁰X = 10 amu
Relative Intensity of ¹⁰X = 23 %
Atomic Mass of ¹¹X = 11 amu
Relative Intensity ¹¹X = 100 %
It means that if there are 123 atoms of this mystery element then then 23 will be of an isotope with atomic mass of 10 amu and the remaining 100 will be of an isotope with atomic mass of 11 amu.
So, we will now calculate the total mass of all elements as;
Total Mass = (23 × 10) + (100 × 11)
Total Mass = (230) + (1100)
Total Mass = 1330 amu
Then, we will calculate the average mass as,
Average Atomic Mass = 1330 / 123
Average Atomic Mass = 10.81