Chapter 3, Problem 3.7EP

(a)

Interpretation Introduction

Interpretation:

The number of protons, neutrons and electrons present in the atom of $\text{S}\text{n}$ 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 $\text{S}\text{n}$.  From this it is understood that the atomic number is 50 and mass number is 118.  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 50 and mass number is given as 118.

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}50\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}50\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}118-50\\ =68\end{array}$

Therefore, the number of protons is 50, number of electrons is 50, and number of neutrons is 68.

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 of $\text{P}\text{t}$ 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 $\text{P}\text{t}$.  From this it is understood that the atomic number is 78 and mass number is 195.  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 78 and mass number is given as 195.

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}78\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}78\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}195-78\\ =117\end{array}$

Therefore, the number of protons is 78, number of electrons is 78, and number of neutrons is 117.

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 of $\text{G}\text{a}$ 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 $\text{G}\text{a}$.  From this it is understood that the atomic number is 72 and mass number is 31.  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 31 and mass number is given as 72.

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}31\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}31\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}72-31\\ =41\end{array}$

Therefore, the number of protons is 31, number of electrons is 31, and number of neutrons is 41.

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 of $\text{M}\text{g}$ 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 $\text{M}\text{g}$.  From this it is understood that the atomic number is 12 and mass number is 26.  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 12 and mass number is given as 26.

  $\begin{array}{l}\text{Number of protons}\text{=}\text{Atomic number}\text{=}12\\ \text{Number of electrons}\text{=}\text{Atomic number}\text{=}12\\ \text{Number of neutrons}\text{=}\text{Mass}\text{number - Atomic number}\text{=}26-12\\ =14\end{array}$

Therefore, the number of protons is 12, number of electrons is 12, and number of neutrons is 14.

Conclusion

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