question_answer

In nature, the element boron occurs 19.9% as \[^{\text{10}}\text{B}\] and 80.1% as\[^{\text{11}}\text{B}\]. If the isotopic mass of \[^{\text{10}}\text{B}\] is 10.013 amu and that of \[^{11}\text{B}\] is 11.009 amu, the atomic mass of boron is

A) 10                               

B) 11                   

C) 10.8    

D)        11.8