Question

boron consists of two isotopes: 10B (19.9%) with an isotopic mass of 10.0129 amu and 11B (80.1%) with an isotopic mass of 11.00931 amu. What is the atomic mass of boron?

Answer 1

The average atomic mass of boron is approximately 10.81 amu.

Step-by-step explanation:

The average atomic mass of boron can be calculated using the percentages and masses of its isotopes. Boron has two isotopes, 10B and 11B, with abundances of 19.9% and 80.1% respectively. The mass of 10B is 10.0129 amu, while the mass of 11B is 11.00931 amu. To calculate the average atomic mass, we multiply the mass of each isotope by its abundance and sum them up:

(0.199)(10.0129 amu) + (0.801)(11.00931 amu) = 10.81 amu

Therefore, the atomic mass of boron is approximately 10.81 amu.