The percentage abundance of two isotopes of boron in a natural sample are 80 and 20. The first isotope has 6 neutrons in the nucleus. If the actual atomic mass of boron is 11.01, calculate the mass numbers of the 2nd isotopes.

Explanation

To solve the problem, we need to find the mass number of the second isotope of boron given the following information:

1. The percentage abundance of the two isotopes of boron is 80% and 20%.
2. The first isotope has 6 neutrons.
3. The actual atomic mass of boron is 11.01.

### Step 1: Identify the mass number of the first isotope.
The mass number (A) of an isotope is the sum of the number of protons (Z) and the number of neutrons (N).
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