Chapter 4, Problem 111A

Interpretation Introduction

Interpretation:

An element has three naturally occurring isotopes. For the calculation of atomic mass of an element the other information needed needs to be explained.

Concept introduction:

Atoms of the same elements with different numbers of neutrons are isotopes. Atomic mass of an element is the weighted average mass of the isotopes of that element.

Answer to Problem 111A

To calculate the element’s atomic mass, the most important information needed is naturally occurring isotopes with their atomic mass and the percentage abundance of each isotopes.

Explanation of Solution

The atomic mass of an element is the average of the isotopicmasses, this is also known as the relative atomic mass.

On comparing the isotopic masses of any given element to the relative atomic mass of the element, it can be seen that the atomic mass is close to the isotope with higher natural abundance. Thus, the isotope whose mass is more close to the atomic mass have highest abundance.

The average atomic mass can be calculated using the following formula:

$(Mas{s}_1\times Abundanc{e}_1)+\left(Mas{s}_2\times Abundanc{e}_2\right)+\left(Mas{s}_3\times Abundanc{e}_3\right)$

Conclusion

The naturally occurring isotopes with atomic mass and the percentage of the abundance of the isotope important term use to calculate the atomic mass of the element.