Chapter 4.3, Problem 19PP

Interpretation Introduction

Interpretation:

The more abundant naturally occurring isotope between N-14 and N-15 needs to be determined if its atomic mass is $14.007$.

Concept introduction:  Isotope is the same number of protons and electrons but have a different number of neutrons in an atom of the same element.

Answer to Problem 19PP

The more abundant isotope is N-14 because the atomic mass is closer to 14 than 15.

Explanation of Solution

Nitrogen is the chemical element which has atomic number 7 in the periodic table. Its symbol is N. It belongs to group 15 and period 2 of the periodic table and is the lightest element in it.

Its average atomic mass is $14.007\text{ amu}$. Among N-14 and N-15, the more abundant isotope is N-14 because the atomic mass is closer to 14 than 15 as the average atomic mass is average value of the masses of all isotopes of the element with respect to their percent abundance.

Conclusion

Hence, isotope N-14 is more abundant than N-15 due to the atomic mass.