Question

007 amu

(a) 15.001 amu

(b) 14.000 amu

(c) 14.0031 amu

The question was posed to me during a job interview.

My enquiry is from Atomic and Molecular Masses in section Chemistry Basic Concepts of Chemistry – Class 11

Answer 1

The correct answer is (a) 15.001 amu

To elaborate: The formula for finding the average atomic mass of an element is given by Avg. Atomic Mass = ∑Abundance of isotope x Mass of isotope. So for nitrogen, avg atomic mass = 99.69 x 14.0031 + 0.39% x 15.0001 = 14.007.