Chapter 1, Problem 1P

Chromium has four isotopes $\text{C}\text{r}$, $\text{C}\text{r}$, $\text{C}\text{r}$ and $\text{C}\text{r}$. How many electrons, protons, and neutrons does each isotope possess?

Interpretation Introduction

Interpretation:

The number of electrons, protons, and neutrons present in the given isotopes of Chromium ($\text{C}\text{r}$, $\text{C}\text{r}$, $\text{C}\text{r}$ and $\text{C}\text{r}$) are to be determined.

Concept Introduction:

Nuclides of the same element possess the same number of protons and electrons but may have different mass number.

Nuclides of a particular element that differ in the number of neutrons and their mass number are called isotopes.

Isotopes of given element have the same number of protons or atomic number but have different number of neutrons in each atom.

Atomic number (Z) = number of protons present in the nucleus of an atom of the element = number of electrons present in a neutral atom of the element

Mass number (A) = number of protons + number of neutrons

Answer to Problem 1P

Solution:

$\text{C}\text{r}$ The number of electrons is 24, number of protons is 24 and number of neutrons is 26

$\text{C}\text{r}$ The number of electrons is 24, number of protons is 24 and number of neutrons is 28

$\text{C}\text{r}$ The number of electrons is 24, number of protons is 24 and number of neutrons is 29

$\text{C}\text{r}$ The number of electrons is 24, number of protons is 24 and number of neutrons is 26

Explanation of Solution

For isotope $\text{C}\text{r}$

Atomic number = number of electrons = number of protons = 24

The number of neutrons = mass number – number of protons = 50-24 = 26

For isotope $\text{C}\text{r}$

Atomic number = number of electrons = number of protons = 24

The number of neutrons = mass number – number of protons = 52-24 = 28

For isotope $\text{C}\text{r}$

Atomic number = number of electrons = number of protons = 24

The number of neutrons = mass number – number of protons = 53-24 = 29

For isotope $\text{C}\text{r}$

Atomic number = number of electrons = number of protons = 24

The number of neutrons = mass number – number of protons = 54-24 = 30