Chapter 4, Problem 101A

Interpretation Introduction

Interpretation:

The mass number of potassium-39 and isotope charge of potassium-39 should be determined.

Concept introduction:

- The mass number of element is the total number of protons and neutrons present in nucleus of an atom.

Isotope charge is generated from an element with loss or gain of electrons. Atoms of the same elements with different numbers of neutrons are isotopes.

Answer to Problem 101A

Mass number is the sum of total num of protons and neutrons in atomic nucleus.

Mass number also known as nucleons number. Mass number of potassium is 39.

The isotope charge is zero.

Explanation of Solution

Mass number formula:

$Massnumber=Atomicnumber+Numberofneutrons$

The mass number of potassium is 39, with atomic number 19 and number of neutrons is 20.

The atomic number is equal to the number of protons present in atomic nucleus.

The isotope charge is zero. There is no loss or gain of electrons by the potassium.

The Potassium has 19 protons.

Conclusion

The mass number of potassium is 39. There is no loss or gain of electrons so the isotope charge of potassium-39 is zero.