Chapter 4, Problem 63A

Interpretation Introduction

Interpretation : The atomic mass of an element from isotope data is to be calculated.

Concept Introduction : Atomic mass is the weighted average mass of the atoms in a sample of an element that is present in nature.

Answer to Problem 63A

For the calculation of atomic mass, multiply each isotope's mass by its natural abundance, represented as a decimal, and add on the products.

The formula to calculate atomic mass is given as:

  $\text{Atomic mass}\text{=}\text{Isotope}\text{mass number}\times \text{Natural percent abundance}$

Explanation of Solution

The weighted average mass of the atoms in a naturally occurring sample of an element is the atomic mass.

Atoms that have various numbers of neutrons and different masses but the same number of protons are called isotopes.

The mass and relative abundance of isotopes as they appear in nature are both reflected in the weighted average mass.

An element's atomic mass is calculated as the weighted average of all of its isotopes' masses.

On relative abundance lies the base.

For the calculation of atomic mass, multiply each isotope's mass by its natural abundance, represented as a decimal, and add on the products.

The formula to calculate atomic mass is given as:

  $\text{Atomic mass}\text{=}\text{Isotope}\text{mass number}\times \text{Natural percent abundance}$