Chapter 3, Problem 3.6EP

(a)

Interpretation Introduction

Interpretation:

The number of protons, neutrons and electrons present in the atom that has atomic number of 8 and mass number of 18 has to be given.

Concept Introduction:

Atomic number for each and every element is a unique one.  This is the total number of protons that is present in an atom.  As the atom is electrically neutral, it can also be said that the total number of electrons is the atomic number.  Atomic number is represented by the symbol Z.

$\text{Atomic number}\text{=}\text{number of protons}\text{=}\text{number of electrons}$

Mass number is the sum of the number of protons and neutrons inside the nucleus of an atom.  This gives the number of subatomic particle present inside the nucleus.  Mass number is represented by the symbol A.

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

From atomic number and mass number, the number of each sub atomic particle can be found.

$\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}A-Z\end{array}$

Complete chemical symbol notation can be given as.

An element is a pure substance that cannot be broken by ordinary chemical reactions into simpler substances.  All the atoms in an element will have the same atomic number.  The electrons only take part in the chemical reaction while the nucleus does not.  Hence, the atomic number (number or protons) does not change and it characterizes an atom.

Explanation of Solution

Given atom is said to have atomic number as 8 and mass number as 18.  The number of protons, electrons and neutrons can be found as shown below,

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}A-Z\end{array}$

Atomic number is given as 8 and mass number is given as 18.

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}8\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}8\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}18-8\\ =10\end{array}$

Therefore, the number of protons is 8, number of electrons is 8, and number of neutrons is 10.

Conclusion

The number of protons, electrons and neutrons present in the atom is given.

(b)

Interpretation Introduction

Interpretation:

The number of protons, neutrons and electrons present in the atom that has atomic number of 19 and mass number of 39 has to be given.

Concept Introduction:

Atomic number for each and every element is a unique one.  This is the total number of protons that is present in an atom.  As the atom is electrically neutral, it can also be said that the total number of electrons is the atomic number.  Atomic number is represented by the symbol Z.

$\text{Atomic number}\text{=}\text{number of protons}\text{=}\text{number of electrons}$

Mass number is the sum of the number of protons and neutrons inside the nucleus of an atom.  This gives the number of subatomic particle present inside the nucleus.  Mass number is represented by the symbol A.

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

From atomic number and mass number, the number of each sub atomic particle can be found.

$\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}A-Z\end{array}$

Complete chemical symbol notation can be given as.

An element is a pure substance that cannot be broken by ordinary chemical reactions into simpler substances.  All the atoms in an element will have the same atomic number.  The electrons only take part in the chemical reaction while the nucleus does not.  Hence, the atomic number (number or protons) does not change and it characterizes an atom.

Explanation of Solution

Given atom is said to have atomic number as 19 and mass number as 39.  The number of protons, electrons and neutrons can be found as shown below,

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}A-Z\end{array}$

Atomic number is given as 19 and mass number is given as 39.

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}19\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}19\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}39-19\\ =20\end{array}$

Therefore, the number of protons is 19, number of electrons is 19, and number of neutrons is 20.

Conclusion

The number of protons, electrons and neutrons present in the atom is given.

(c)

Interpretation Introduction

Interpretation:

The number of protons, neutrons and electrons present in the atom which has Z as 18 and A as 40 has to be given.

Concept Introduction:

Atomic number for each and every element is a unique one.  This is the total number of protons that is present in an atom.  As the atom is electrically neutral, it can also be said that the total number of electrons is the atomic number.  Atomic number is represented by the symbol Z.

$\text{Atomic number}\text{=}\text{number of protons}\text{=}\text{number of electrons}$

Mass number is the sum of the number of protons and neutrons inside the nucleus of an atom.  This gives the number of subatomic particle present inside the nucleus.  Mass number is represented by the symbol A.

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

From atomic number and mass number, the number of each sub atomic particle can be found.

$\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}A-Z\end{array}$

Complete chemical symbol notation can be given as.

An element is a pure substance that cannot be broken by ordinary chemical reactions into simpler substances.  All the atoms in an element will have the same atomic number.  The electrons only take part in the chemical reaction while the nucleus does not.  Hence, the atomic number (number or protons) does not change and it characterizes an atom.

Explanation of Solution

Given atom is said to have Z as 18 and A as 40.  The number of protons, electrons and neutrons can be found as shown below,

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}A-Z\end{array}$

Atomic number is given as 18 and mass number is given as 40.

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}18\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}18\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}40-18\\ =22\end{array}$

Therefore, the number of protons is 18, number of electrons is 18, and number of neutrons is 22.

Conclusion

The number of protons, electrons and neutrons present in the atom is given.

(d)

Interpretation Introduction

Interpretation:

The number of protons, neutrons and electrons present in the atom which has Z as 24 and A as 52 has to be given.

Concept Introduction:

Atomic number for each and every element is a unique one.  This is the total number of protons that is present in an atom.  As the atom is electrically neutral, it can also be said that the total number of electrons is the atomic number.  Atomic number is represented by the symbol Z.

$\text{Atomic number}\text{=}\text{number of protons}\text{=}\text{number of electrons}$

Mass number is the sum of the number of protons and neutrons inside the nucleus of an atom.  This gives the number of subatomic particle present inside the nucleus.  Mass number is represented by the symbol A.

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

From atomic number and mass number, the number of each sub atomic particle can be found.

$\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}A-Z\end{array}$

Complete chemical symbol notation can be given as.

An element is a pure substance that cannot be broken by ordinary chemical reactions into simpler substances.  All the atoms in an element will have the same atomic number.  The electrons only take part in the chemical reaction while the nucleus does not.  Hence, the atomic number (number or protons) does not change and it characterizes an atom.

Explanation of Solution

Given atom is said to have Z as 24 and A as 52.  The number of protons, electrons and neutrons can be found as shown below,

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}Z\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}A-Z\end{array}$

Atomic number is given as 24 and mass number is given as 52.

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}24\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}24\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}52-24\\ =28\end{array}$

Therefore, the number of protons is 24, number of electrons is 24, and number of neutrons is 28.

Conclusion

The number of protons, electrons and neutrons present in the atom is given.