Question

The atomic mass and abundance of Cr-50 is 49.946 amu and 4.3%. The atomic mass and abundance of Cr-52 is 51.941 amu and 83.8%. The atomic mass and abundance of Cr-53 is 52.941 amu and 9.5%. The atomic mass and abundance of Cr-54 is 53.939 amu and 2.4%. Which is the average atomic mass of chromium?
a. 53.94 amu
b. 52.19 amu
c. 52.00 amu
d. 51.94 amu

Answer 1

Multiply the mass by the abundance and add each. Make sure to convert the percentage into a decimal. (49.946 * .043) + (51.941 * .838) + (52.941 * .095) + (53.939 * .024) = 51.99 round up using sig figs and the answer is c. 52.00 amu