Chapter 4, Problem 68A

Mercury An isotope of mercury has 80 protons and 120 neutrons. What is the mass number of this isotope?

Interpretation Introduction

Interpretation:

Mass number of an isotope of mercury with 80 protons and 120 neutrons is to be calculated.

Concept introduction:

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

Answer to Problem 68A

$\text{Mass number = 200}$

Explanation of Solution

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

Therefore,

$\begin{array}{l}\text{Mass number = Number of protons +Number of neutrons}\hfill \\ \text{ = 80 + 120}\hfill \\ \text{ = 200 }\hfill \end{array}$

Mass number is 200

Conclusion

An isotopes of mercury with 80 protons and 120 neutrons have a mass number of 200