Chemistry · Some Basic Concepts of Chemistry

Consider the following statements regarding carbon isotopes and average atomic mass: (A) Carbon-12 is assigned an atomic mass of exactly \( 12\text{ amu} \). (B) The relative abundance of \( ^{13}\text{C} \) is approximately \( 1.108\% \). (C) The average atomic mass of naturally occurring carbon is approximately \( 12.011\text{ u} \). (D) The average atomic mass of an element is obtained by multiplying the mass of each isotope by its fractional abundance and summing them. How many of the above statements are correct?

1. Only one
2. Only two
3. Only three
4. All four