Chapter 19, Problem 58A

Interpretation Introduction

Interpretation: The number of protons and neutron of each isotopes of aluminium needs to be determined.

Concept introduction: The subscript in symbol of element represents number of protons and superscript represents mass number.

Number of neutron $=$ mass number − number of protons

Answer to Problem 58A

Isotopes	Number of protons	Number of neutrons
$Al$	13	14
$Al$	13	15
$Al$	13	16

Explanation of Solution

Protons number of all isotopes will be same (13) but number of neutrons will vary as mass number is different for isotopes.

For $Al$ number of neutrons $=27-13=14$

For $Al$ number of neutrons $=28-13\text{ = }15$

For $Al$ number of neutrons $=29-13\text{ = }16$

Conclusion

Isotopes	Number of protons	Number of neutrons
$Al$	13	14
$Al$	13	15
$Al$	13	16