Question

calculate the average atomic mass of carbon if 98.90% of the atoms are c - 12 (12.000000 amu) and 1.100% are c - 13 atoms (13.003354 amu). type in your answer using 2 decimal places.
m_a for carbon = amu

Explanation:

Step1: Convert percentages to decimals

$98.90\%=0.9890$ and $1.100\% = 0.01100$

Step2: Calculate the contribution of each isotope

For C - 12: $0.9890\times12.00000=11.868$
For C - 13: $0.01100\times13.003354 = 0.143036894$

Step3: Sum the contributions

$11.868+0.143036894=12.011036894$

Answer:

$12.01$ amu