Final answer:
The abundance of boron isotopes can be determined by the given atomic weight of boron (10.81 amu). Since this value is closer to the mass of B-11 (11.01 amu) than B-10 (10.01 amu), we can infer that B-11 is more abundant.
Step-by-step explanation:
The question asks to determine which isotope of boron is more abundant based on the given atomic weight of boron (10.81 amu). To solve this, we can use the fact that the atomic weight of an element is the weighted average of the masses of its isotopes, proportional to their abundances. Given two isotopes of boron, B-10 with a mass of 10.01 amu and B-11 with a mass of 11.01 amu, the atomic weight of boron is given as 10.81 amu.
Since the atomic weight is closer to the mass of B-11 than B-10, this suggests that B-11 is more abundant. The exact abundances of each isotope can be determined using the following formula:
(Percent abundance of B-10)×(Mass of B-10) + (Percent abundance of B-11)×(Mass of B-11) = Average atomic mass of boron (10.81 amu).
Since the average atomic mass is closer to the mass of B-11, we can conclude that the isotope B-11 is significantly more abundant than B-10.