Question

Calculate the average atomic mass of carbon if 98.90% of the atoms are C-12 ( 12.000000amu) and 1.10% are C-13 atoms ( 13.003354amu). Type in your answer using 2 decimal places. MA for carbon =

amu
amu.
a) 12.00
b) 12.01
c) 12.02
d) 12.03

Answer 1

The average atomic mass of carbon is (c) 12.02 amu, which is close to the atomic mass listed on the periodic table of 12.011 amu.

Step-by-step explanation:

The average atomic mass of carbon is calculated by taking into account the relative abundance of each isotope of carbon and multiplying it by its mass. In this case, 98.90% of the atoms are C-12 and 1.10% are C-13.

The atomic masses of C-12 and C-13 are 12.000000 amu and 13.003354 amu, respectively.

To calculate the average atomic mass, we multiply the abundance of each isotope by its atomic mass and then sum them up:

(0.9890 × 12 amu) + (0.0110 × 13.003354 amu) = 12.0112 amu.

Therefore, the correct answer is c) 12.02.