Chapter 2, Problem 2.60AP

(a)

Interpretation Introduction

Interpretation:

The number of protons for the three isotopes of Tin has to be given.

Concept Introduction:

Protons:

A proton is one of three main particles that make up the atom.  Protons are a tiny, dense region at the center of the atom.  Protons have a positive electrical charge of $+1$ and a mass of 1 atomic mass which is $\text{1}{\text{.62×10}}^{\text{-27}}$ kilograms.

Explanation of Solution

Given,

The atomic number of Tin is $50.$

  $\text{Atomic number of an element=The number of protons}$

Thus the number of protons for three isotopes of Tin (Tin-116, Tin-118 and Tin-120) is $50.$

(b)

Interpretation Introduction

Interpretation:

The number of neutrons for the three isotopes of Tin has to be given.

Concept Introduction:

Neutrons:

Atoms of all elements except for most atoms of hydrogen have neutrons in their nucleus. Unlike protons and electrons, which are electrically charged, neutrons have no charge they are electrically neutral.

Explanation of Solution

Given,

The mass number of three Tin isotopes is $116,118,120.$

The number of protons in three Tin isotopes is $50.$

The mass number of Tin -116 can be calculated as,

  $\text{A=Number}\text{of}\text{protons}\text{+}\text{Number}\text{of}\text{neutrons}$

  $\begin{array}{l}\text{Number}\text{of}\text{neutrons=A-Number}\text{of}\text{protons}\\ \text{Number}\text{of}\text{neutrons=116-50}\\ \text{Number}\text{of}\text{neutrons=66}\end{array}$

The mass number of Tin -116 is $66.$

The mass number of Tin -118 can be calculated as,

  $\text{A=Number}\text{of}\text{protons}\text{+}\text{Number}\text{of}\text{neutrons}$

  $\begin{array}{l}\text{Number}\text{of}\text{neutrons=A-Number}\text{of}\text{protons}\\ \text{Number}\text{of}\text{neutrons=118-50}\\ \text{Number}\text{of}\text{neutrons=68}\end{array}$

The mass number of Tin -118 is $68.$

The mass number of Tin -120 can be calculated as,

  $\text{A=Number}\text{of}\text{protons}\text{+}\text{Number}\text{of}\text{neutrons}$

  $\begin{array}{l}\text{Number}\text{of}\text{neutrons=A-Number}\text{of}\text{protons}\\ \text{Number}\text{of}\text{neutrons=120-50}\\ \text{Number}\text{of}\text{neutrons=70}\end{array}$

The mass number of Tin -120 is $70.$

(c)

Interpretation Introduction

Interpretation:

The number of electrons for the three isotopes of Tin has to be given.

Concept Introduction:

Electrons:

Electrons have an electric charge of $\text{-1}$, which is equal but opposite to the charge of a proton, which have an electric charge of $\text{+1}\text{.}$  All atoms have the same number of electrons as protons, so the positive and negative charges cancel out making atoms electrically neutral.

Explanation of Solution

Given,

The atomic number of Tin is $50.$

  $\text{Atomic number of an element=The number of electrons}$

Thus the number of electrons for three isotopes of Tin (Tin-116, Tin-118 and Tin-120) is $50.$

(d)

Interpretation Introduction

Interpretation:

The group number of Tin has to be given.

Explanation of Solution

The Tin is placed as fourth element in group-14 of the periodic table and is considered among the main group elements.

(e)

Interpretation Introduction

Interpretation:

The isotopic symbol of three Tin isotopes has to be given.

Explanation of Solution

The isotopic symbol of Tin-116 is,

Given,

The atomic number is $50.$

The mass number is $116.$

The isotopic symbol of the Tin-116 is given by writing the atomic number on the subscript and the mass number on the superscript.  Thus, the isotopic symbol of Tin-116 is ${{}_{50}}^{116}\text{Sn}\text{.}$

The isotopic symbol of Tin-118 is,

Given,

The atomic number is $50.$

The mass number is $118.$

The isotopic symbol of the Tin-118 is given by writing the atomic number on the subscript and the mass number on the superscript.  Thus, the isotopic symbol of Tin-118 is ${{}_{50}}^{118}\text{Sn}\text{.}$

The isotopic symbol of Tin-120 is,

Given,

The atomic number is $50.$

The mass number is $120.$

The isotopic symbol of the Tin-120 is given by writing the atomic number on the subscript and the mass number on the superscript.  Thus, the isotopic symbol of Tin-120 is ${{}_{50}}^{120}\text{Sn}\text{.}$