Question

Carbon has three naturally occurring isotopes, C-12, C-13, and C-14. C-12 has a natural abundance of 98.93% and an isotopic mass of 12.000000 amu. C-13 has a natural abundance of 1.07% and an isotopic mass of 13.003355 amu, and C-14 has a trace (or negligible) natural abundance and an isotopic mass of 14.003242 amu. What is the atomic weight of carbon?

Options:
Option 1: Approximately 12.01 amu
Option 2: Approximately 13.00 amu
Option 3: Approximately 14.00 amu
Option 4: Approximately 1.07 amu

Answer 1

The atomic weight of carbon is approximately 1) 12.01 amu.

Step-by-step explanation:

The atomic weight of carbon can be calculated using the formula:

(Abundance of C-12 x Mass of C-12) + (Abundance of C-13 x Mass of C-13) + (Abundance of C-14 x Mass of C-14)

Substituting the given values, we get:

(0.9893 x 12.000000 amu) + (0.0107 x 13.003355 amu) + (0 x 14.003242 amu) = Approximately 12.01 amu

Therefore, the atomic weight of carbon is approximately 12.01 amu.