Chapter 4, Problem 60A

How is the mass number related to the number of protons and neutrons an atom has?

Interpretation Introduction

Interpretation:

Relation of Mass number with number of protons and neutrons needs to be explained.

Concept introduction:

Mass Number is number of nucleons present in the nucleus of an atom.

Nucleus consists positively charged particles known as protons and neutral particles known as neutrons.

Answer to Problem 60A

$\text{Mass number = Number of proton + Number of neutrons }$

Explanation of Solution

Nucleons are the total particles present in a nucleus. Nucleus is positively charged because it has positively charged particle known as protons and neutral particles neutrons.

Mass number is a total number of nucleons present in the nucleus of an atom.

$\begin{array}{l}\text{Mass number = Number of nucleons}\hfill \\ \text{Number of nucleons = Number of protons + Number of neutrons}\hfill \\ \therefore \text{Mass number = Number of protons + Number of neutrons}\hfill \end{array}$

Conclusion

Mass number is the sum of all protons and neutrons present in the nucleus of an atom.