Chapter 10, Problem 22P

Interpretation Introduction

(a)

Interpretation:

The following table of isotopes should be completed:

  

Concept Introduction:

Isotopes are the compounds having the same atomic number but different atomic mass.

To write an isotope symbol atomic number (Z) is written on the lower left side and atomic mass (A) is written on the upper left side of an element.

Answer to Problem 22P

The complete table for isotopes symbol is represented as follows:

	Atomic number(Z)	Mass number(A)	Number of protons	Number of neutrons	Isotope symbol
Sodium-24	11	24	11	13	${}_{11}^{\text{24}}\text{Na}$

Explanation of Solution

The atomic number is equal to the number of protons in an element.

Mass number = Number of protons + Number of neutrons

The atomic number for sodium is 11 and the mass number is 24.

Since atomic number = number of protons

Thus, the number of protons in sodium is 11 and the number of neutrons in sodium can be calculated by simply subtracting the number of protons from the mass number as follows:

  $\begin{array}{c}\text{Mass number = Number of protons + Number of neutrons}\\ 24\text{=}11\text{+}\text{ Number of neutrons}\\ \text{Number of neutrons}=24-11\\ =13\end{array}$

Therefore, the isotope symbol for Sodium is ${}_{11}^{\text{24}}\text{Na}$.

Interpretation Introduction

(b)

Interpretation:

The following table of isotopes should be completed:

  

Concept Introduction:

Isotopes are the compounds having the same atomic number but different atomic mass.

To write an isotope symbol atomic number (Z) is written on the lower left side and atomic mass (A) is written on the upper left side of an element.

Answer to Problem 22P

The complete table for isotopes symbol is represented as follows:

	Atomic number(Z)	Mass number(A)	Number of protons	Number of neutrons	Isotope symbol
b. Strotium-89	38	89	38	51	${}_{\text{38}}^{89}\text{Sr}$

Explanation of Solution

The formula to determine the mass number is:

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

Rearranging:

  $\text{Number of protons = Mass number}-\text{ Number of neutrons}$

Substituting the values:

  $\begin{array}{l}\text{Number of protons = 89}-\text{ 51}\\ \text{Number of protons = 38}\end{array}$

Since atomic number = number of protons

Thus, the element with atomic number 38 is strontium, Sr.

Therefore, the isotope symbol for strontium is ${}_{\text{38}}^{89}\text{Sr}$.

Interpretation Introduction

(c)

Interpretation:

The following table of isotopes should be completed:

  

Concept Introduction:

Isotopes are the compounds having the same atomic number but different atomic mass.

To write an isotope symbol atomic number(Z) is written on the lower left side and atomic mass(A) is written on the upper left side of an element.

Answer to Problem 22P

The complete table for isotopes symbol is represented as follows:

	Atomic number(Z)	Mass number(A)	Number of protons	Number of neutrons	Isotope symbol
c. Iron-59	26	59	26	33	${}_{\text{26}}^{\text{59}}\text{Fe}$

Explanation of Solution

The mass number of element is 59.

Since atomic number = number of protons

So, the atomic number of the isotope is 26 thus, the element is iron, Fe.

Thus, the number of protons for this element is 26 and the number of neutrons in iron can be calculated by simply subtracting the number of protons from the mass number as follows:

  $\begin{array}{c}\text{Mass number = Number of protons + Number of neutrons}\\ 59\text{=}26\text{+}\text{ Number of neutrons}\\ \text{Number of neutrons}=59-26\\ =33\end{array}$

Therefore, the isotope symbol for iron is ${}_{\text{26}}^{\text{59}}\text{Fe}$.

Interpretation Introduction

(d)

Interpretation:

The following table of isotopes should be completed:

  

Concept Introduction:

Isotopes are the compounds having the same atomic number but different atomic mass.

To write an isotope symbol atomic number(Z) is written on the lower left side and atomic mass(A) is written on the upper left side of an element.

Answer to Problem 22P

The complete table for isotopes symbol is represented as follows:

	Atomic number(Z)	Mass number(A)	Number of protons	Number of neutrons	Isotope symbol
d.Samarium-153	62	153	62	91	${}_{\text{62}}^{\text{153}}\text{Sm}$

Explanation of Solution

The mass number of element is 153.

The atomic number of samarium is 62.

Since atomic number = number of protons

Thus, the number of protons for this element is 62 and the number of neutrons in samarium can be calculated by simply subtracting the number of protons from the mass number as follows:

  $\begin{array}{c}\text{Mass number = Number of protons + Number of neutrons}\\ 153\text{=}62\text{+}\text{ Number of neutrons}\\ \text{Number of neutrons}=153-62\\ =91\end{array}$

Therefore, the isotope symbol for Samarium is ${}_{\text{62}}^{\text{153}}\text{Sm}$.