Chapter 20, Problem 60E

Interpretation Introduction

(a)

Interpretation:

Whether the statement, “A radioactive element decays in the same way, whether or not the atom is chemically bonded in a compound” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “A radioactive element decays in the same way, whether or not the atom is chemically bonded in a compound” is true.

Explanation of Solution

Radioactivity of an element is the property of its nucleus. It is not dependent on electronic configuration. As a result, a radioactive element decays in the same way when it is bonded in a compound as when it is unbonded. Therefore, the statement, “A radioactive element decays in the same way, whether or not the atom is chemically bonded in a compound” is true.

Conclusion

The given statement is true.`

Interpretation Introduction

(b)

Interpretation:

Whether the statement, “The chemical properties of a radioactive atom of an element are different from the chemical properties of the same element” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “The chemical properties of a radioactive atom of an element are different from the chemical properties of the same element” is false.

Explanation of Solution

Radioactivity of an element is the property of its nucleus.It is not dependent on electronic configuration. The chemical properties of an element depend upon the electronic configuration. It does not depend upon the nuclear structure. As a result, the chemical properties of a radioactive atom of an element is the same as that of the element. Therefore the statement, “The chemical properties of a radioactive atom of an element are different from the chemical properties of the same element” is false.

Conclusion

The given statement is false.

Interpretation Introduction

(c)

Interpretation:

Whether the statement, “$\text{α-}$ particles have more penetrating power than $\text{β-}$ particles” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive

Answer to Problem 60E

The statement, “$\text{α-}$ particles have more penetrating power than $\text{β-}$ particles” is false.

Explanation of Solution

Alpha radiations are soft radiations. They have very little penetrating power. They consist of positively charged particles. Beta radiations have more penetrating power than alpha radiations. They consist of negatively charged particles. Therefore, the statement, “$\text{α-}$ particles have more penetrating power than $\text{β-}$ particles” is false.

Conclusion

The given statement is false.

Interpretation Introduction

(d)

Interpretation:

Whether the statement, “$\text{α-}$ and $\text{β-}$ emissions are particles but a $\text{γ-}$ ray is an “energy ray”” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “$\text{α-}$ and $\text{β-}$ emissions are particles but a $\text{γ-}$ ray is an “energy ray”” is true.

Explanation of Solution

Radioactive decay is a spontaneous disintegration process in which one unstable nucleus is converted to a stable nucleus with the emission of $\text{α-}$ particle, $\text{β-}$ particle, and $\text{γ-}$ ray. $\text{γ-}$ rays are neutral in nature. Therefore, the statement, “$\text{α-}$ and $\text{β-}$ emissions are particles but a $\text{γ-}$ ray is an “energy ray”” is true.

Conclusion

The given statement is true.

Interpretation Introduction

(e)

Interpretation:

Whether the statement, “Radioactivity is a nuclear change that has no effect on the electrons in the nearby atoms” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “Radioactivity is a nuclear change that has no effect on the electrons in the nearby atoms” is false.

Explanation of Solution

Radioactivity of an element can ionize the nearby atoms. The ionization of the nearby atoms can change the electronic arrangement of the atoms. This means that the radioactivity has an effect on the electrons in the nearby atoms. Therefore, the statement, “Radioactivity is a nuclear change that has no effect on the electrons in the nearby atoms” is false.

Conclusion

The given statement is false.

Interpretation Introduction

(f)

Interpretation:

Whether the statement, “The number of protons in a nucleus changes when it emits a $\text{β-}$ particle” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “The number of protons in a nucleus changes when it emits a $\text{β-}$ particle” is true.

Explanation of Solution

$\text{β-}$ particles are negatively charged. They are high energy electrons represented by ${}_{-1}^0\text{e}$. As a result, $\text{β-}$ particle emission causes the number of protons to increase by one unit. Therefore, the statement, “The number of protons in a nucleus changes when it emits a $\text{β-}$ particle” is true.

Conclusion

The given statement is true.

Interpretation Introduction

(g)

Interpretation:

Whether the statement, “The mass number of a nucleus changes in an alpha emission but not in a beta emission” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “The mass number of a nucleus changes in an alpha emission but not in a beta emission” is true.

Explanation of Solution

The $\text{α-}$ particles are positively charged. They are doubly charged helium atom. They are represented by the symbol, ${}_2^4\text{He}$. Mass number of $\text{α-}$ particle is $4$. $\text{β-}$ particles are negatively charged. They are high energy electrons represented by ${}_{-1}^0\text{e}$. The mass number of $\text{β-}$ particle is $0$. Therefore, the statement, “The mass number of a nucleus changes in an alpha emission but not in a beta emission” is true.

Conclusion

The statement, “The mass number of a nucleus changes in an alpha emission but not in a beta emission” is true.

Interpretation Introduction

(h)

Interpretation:

Whether the statement, “Synthetic radioisotopes have no application in everyday life or industry; they are used only for scientific research purposes” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “Synthetic radioisotopes have no application in everyday life or industry; they are used only for scientific research purposes” is false.

Explanation of Solution

Isotopes of an element have the same atomic number but a different mass number. The different mass number arises due to different number of neutrons. Isotopes of an element undergoing spontaneous nuclear reactions are known as radioisotopes. They have a wide range of applications in the industry. Therefore, the statement, “Synthetic radioisotopes have no application in everyday life or industry; they are used only for scientific research purposes” is false.

Conclusion

The given statement is false.

Interpretation Introduction

(i)

Interpretation:

Whether the statement, “The first transmutations were achieved by alchemists” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “The first transmutations were achieved by alchemists” is false.

Explanation of Solution

Transmutation is a type of nuclear reaction. It is the induced conversion of one element into the other. The experiments for transmutation were first carried out by Patrick Blackett between $1921$ to $1924$. Therefore, the statement, “The first transmutations were achieved by alchemists” is false.

Conclusion

The given statement is false.

Interpretation Introduction

(j)

Interpretation:

Whether the statement, “Radioisotopes can be made by bombarding a non-radioactive isotope with atomic nuclei or subatomic particle” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive.

Answer to Problem 60E

The statement, “Radioisotopes can be made by bombarding a non-radioactive isotope with atomic nuclei or subatomic particle” is true.

Explanation of Solution

Isotopes of an element have the same atomic number but a different mass number. The different mass number arises due to different number of neutrons. Isotopes of an element undergoing spontaneous nuclear reactions are known as radioisotopes. Radioisotopes can be made by bombarding a non-radioactive isotope. Therefore, the statement, “Radioisotopes can be made by bombarding a non-radioactive isotope with atomic nuclei or subatomic particle” is true.

Conclusion

The given statement is true.

Interpretation Introduction

(k)

Interpretation:

Whether the statement, “The atomic numbers of products of a fission reaction are smaller than the atomic number of the original nucleus” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive. The process by which a radioactive nucleus splits to give two nuclei of smaller masses is known as nuclear fission.

Answer to Problem 60E

The statement, “The atomic numbers of products of a fission reaction are smaller than the atomic number of the original nucleus” is true.

Explanation of Solution

In nuclear fission reactions, a larger nucleus splits to give two nuclei of smaller masses. The reaction is accompanied by the emission of heat. Therefore, the statement, “The atomic numbers of products of a fission reaction are smaller than the atomic number of the original nucleus” is true.

Conclusion

The given statement is true.

Interpretation Introduction

(l)

Interpretation:

Whether the statement, “Nuclear power plants are a safe source of electrical energy” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive. The process by which a radioactive nucleus splits to give two nuclei of smaller masses is known as nuclear fission.

Answer to Problem 60E

The statement, “Nuclear power plants are a safe source of electrical energy” is false.

Explanation of Solution

The disadvantages of using nuclear power plants over other electrical sources are extremely grave. The harmful effects of the accidental leaks, such as the accidental leak of radiation from the nuclear power plant in Chernobyl can be seen in the area even after $33$ years of the incident. Therefore, the statement, “Nuclear power plants are a safe source of electrical energy” is false.

Conclusion

The given statement is false.

Interpretation Introduction

(m)

Interpretation:

Whether the statement, “The main obstacle for developing nuclear fusion as a source of electrical energy is a shortage of nuclei to serve as “fuel” ” is true or false is to be stated.

Concept introduction:

The elements whose nucleus decays spontaneously are known as radioactive elements. The decay is accompanied by the emission of alpha particles, beta particles, and gamma rays. All the elements which have an atomic number greater than $83$ are radioactive. In fusion reactions, a larger nucleus is formed by the combination of two small nuclei.

Answer to Problem 60E

The statement, “The main obstacle for developing nuclear fusion as a source of electrical energy is a shortage of nuclei to serve as “fuel”” is false.

Explanation of Solution

Fusion reactions cannot be triggered internally. They require very high temperatures to commence. Suitable technologies to reach such high temperatures have not been developed yet. Therefore, the statement, “The main obstacle for developing nuclear fusion as a source of electrical energy is a shortage of nuclei to serve as “fuel”” is false.

Conclusion

The given statement is false.