Chapter 2, Problem 2.30QP

(a)

Interpretation Introduction

Interpretation:

It has to be indicated that the isotope which would expect to be radioactive, from the given pair of isotopes.

Concept introduction:

• The elements with same atomic number and different mass number are known as isotopes.
• Radioactive isotopes are the isotopes whose nuclei do not hold together well.
• The belt of stability is the area in a graph of the number of neutrons versus the number of proton in various isotopes where the stable nuclei are located. Most radioactive nuclei lie outside this belt. And their $\frac{\text{n}}{\text{p}}$ ratio is greater than 1.
• A graph (Figure 1) consists of a Y- axis labeled neutrons, and in X- axis labelled protons, and which is used to identify the stability of elements is known as belt of stability.
•  

  

  Figure 1

• The elements with same atomic number and different mass number are known as isotopes. Most of the elements have isotopes, in which many of them are stable and unstable.
• The neutron: proton ratio for stable elements is 1:1 and the elements with atomic numbers up to about 20 are stable.
• The ratio between the numbers of neutrons to the number of proton for an element is referred as  $\frac{\text{n}}{\text{p}}$ ratio.
• The elements beyond the atomic number of 83 are only unstable radioactive elements.
• The neutron: proton ratio ($\frac{\text{n}}{\text{p}}$ ratio) for stable elements is 1:1 and the elements with atomic numbers up to about 20 are stable.
• Half-life (${\text{t}}_{\text{1/2}}$ ) is the time required for a quantity to reduce to half of its initial value.

(b)

Interpretation Introduction

Interpretation:

It has to be indicated the isotope which would expect to be radioactive, from the given pair of isotopes.

Concept introduction:

• The elements with same atomic number and different mass number are known as isotopes.
• Radioactive isotopes are the isotopes whose nuclei do not hold together well.
• The belt of stability is the area in a graph of the number of neutrons versus the number of proton in various isotopes where the stable nuclei are located. Most radioactive nuclei lie outside this belt. And their $\frac{\text{n}}{\text{p}}$ ratio is greater than 1.
• A graph (Figure 1) consists of a Y- axis labeled neutrons, and in X- axis labelled protons, and which is used to identify the stability of elements is known as belt of stability.
•  

  

  Figure 1

• The elements with same atomic number and different mass number are known as isotopes. Most of the elements have isotopes, in which many of them are stable and unstable.
• The neutron: proton ratio for stable elements is 1:1 and the elements with atomic numbers up to about 20 are stable.
• The ratio between the numbers of neutrons to the number of proton for an element is referred as  $\frac{\text{n}}{\text{p}}$ ratio.
• The elements beyond the atomic number of 83 are only unstable radioactive elements.
• The neutron: proton ratio ($\frac{\text{n}}{\text{p}}$ ratio) for stable elements is 1:1 and the elements with atomic numbers up to about 20 are stable.
• Half-life (${\text{t}}_{\text{1/2}}$) is the time required for a quantity to reduce to half of its initial value.

(c)

Interpretation Introduction

Interpretation:

It has to be indicated the isotope which would expect to be radioactive, from the given pair of isotopes.

Concept introduction:

• The elements with same atomic number and different mass number are known as isotopes.
• Radioactive isotopes are the isotopes whose nuclei do not hold together well.
• The belt of stability is the area in a graph of the number of neutrons versus the number of proton in various isotopes where the stable nuclei are located. Most radioactive nuclei lie outside this belt. And their $\frac{\text{n}}{\text{p}}$ ratio is greater than 1.
• A graph (Figure 1) consists of a Y- axis labeled neutrons, and in X- axis labelled protons, and which is used to identify the stability of elements is known as belt of stability.
•  

  

  Figure 1

• The elements with same atomic number and different mass number are known as isotopes. Most of the elements have isotopes, in which many of them are stable and unstable.
• The neutron: proton ratio for stable elements is 1:1 and the elements with atomic numbers up to about 20 are stable.
• The ratio between the numbers of neutrons to the number of proton for an element is referred as  $\frac{\text{n}}{\text{p}}$ ratio.
• The elements beyond the atomic number of 83 are only unstable radioactive elements.
• The neutron: proton ratio ($\frac{\text{n}}{\text{p}}$ ratio) for stable elements is 1:1 and the elements with atomic numbers up to about 20 are stable.
• Half-life (${\text{t}}_{\text{1/2}}$) is the time required for a quantity to reduce to half of its initial value.