Question

multiple - choice question
which is true about the average atomic mass of boron?
its equal to the mass of the most abundant isotope.
its closest to the mass of the least abundant isotope.
its equal to the mass of the least abundant isotope.
its closest to the mass of the most abundant isotope.

Explanation:

The average atomic mass of an element is calculated as a weighted average of the masses of its isotopes. The more abundant an isotope is, the more it contributes to the average atomic mass. So, the average atomic mass is closest to the mass of the most abundant isotope.

Answer:

It's closest to the mass of the most abundant isotope.