Answer:
The relative atomic mass of element E is 20.2.
Explanation:
Calculate the relative atomic mass of element E using the weighted average of the isotopic masses and their abundances.
We know 10% of the atoms have a mass number of 22 (abundance = 0.1).
The remaining 90% of the atoms have a mass number of 20 (abundance = 0.9).
Calculate Weighted Average:The relative atomic mass is the average mass of all isotopes weighted by their abundance.
We can calculate it using the following formula:
Relative atomic mass = (abundance₁ * mass₁) + (abundance₂ * mass₂)
=> (0.1 * 22) + (0.9 * 20) = 20.2