Chapter 9, Problem 9.18P

Interpretation Introduction

(a)

Interpretation:

To analyse whether the given statement -The majority (greater than 50%) of the more than 300 naturally occurring isotopes are stable is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

The statement is true.

Explanation of Solution

The given statement is true because out of 300 naturally occurring isotopes, there are 264 isotopes that are stable and never give off any radioactivity.

Interpretation Introduction

(b)

Interpretation:

To analyse whether the given statement −More artificial isotopes have been created in the laboratory than there are naturally occurring stable isotopes, is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

More artificial isotopes have been created in the laboratory than there are naturally occurring stable isotopes. Thus, the statement is true.

Explanation of Solution

There are more than 1000 isotopes which have been created in laboratory.

Interpretation Introduction

(c)

Interpretation:

To analyse whether the given statement -All artificial isotopes created in the laboratory are radioactive, is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

All artificial isotopes created in the laboratory are radioactive. Thus, the statement is true.

Explanation of Solution

From naturally occurring isotopes 264 isotopes are not having any type of radioactivity. Therefore, more than 1000 artificial isotopes are created which are radioactive.

Interpretation Introduction

(d)

Interpretation:

To analyse whether the given statement - The terms “beta particles”, “beta emission” and “beta ray” all refer to the same type of radiation, is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

The terms “beta particles”, “beta emission” and “beta ray” all refer to the same type of radiation. Thus, the statement is true.

Explanation of Solution

All the three terms- beta ray, bera emission and beta particle are refering to the emissin of electron from given nucleus that results into increase of one number in atomic number of new element and no change in mass number.

Interpretation Introduction

(e)

Interpretation:

To analyse whether the given statement - When balancing a nuclear equation, the sum of the mass numbers and the sum of the atomic numbers on each side of the equation must be the same, is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When balancing a nuclear equation, the sum of the mass numbers and the sum of the atomic numbers on each side of the equation must be the same. Thus, the statement is true.

Explanation of Solution

Any reaction comes in equilibrium when both side of equation is equal. In nuclear reaction, emission of proton or neutron occurs. This made changes in mass number or atomic number or both. So, the nuclear reaction can be balanced with equalization of both sides in its sum of mass number as well as the sum of atomic numbers.

Interpretation Introduction

(f)

Interpretation:

To analyse whether the given statement -The symbol of a beta particle is $\beta$ ,is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

The symbol of a beta particle is $\text{e}$.Thus, the statement is false.

Explanation of Solution

As there is an occurrence of emission of electron which is negatively charged, beta emission has symbol of $\text{e}$.

Interpretation Introduction

(g)

Interpretation:

To analyse whether the given statement - When a nucleus emits a beta particle, the new nucleus has the same mass number but an atomic number one unit higher, is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When a nucleus emits a beta particle, the new nucleus has the same mass number but an atomic number one unit higher. Thus, the statement is true.

Explanation of Solution

During the beta emission, a neutron is converted into proton and electron from which electron is emitted and proton left behind resulted into increase of one in atomic number.

Interpretation Introduction

(h)

Interpretation:

To analyse whether the given statement - When iron-59 ($\text{F}\text{e}$) emits a beta particle, it is converted to cobalt-59 ($\text{C}\text{O}$) is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When iron-59 ($\text{F}\text{e}$) emits a beta particle, it is converted to cobalt-59 ($\text{C}\text{O}$). Thus, the statement is true.

Explanation of Solution

In periodic table, cobalt comes after iron and contains one number more in atomic number. The iron-59 emits electron by decay of its neutron in beta emission. The remaining proton increase the atomic number and forms cobalt-59.

Interpretation Introduction

(i)

Interpretation:

To analyse whether the given statement - When a nucleus emits a beta particle, it first captures an electron from outside the nucleus and then emits it, is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When a nucleus emits a beta particle, neutron is broken down into and electron is emitted as beta particle. Thus, the statement is false.

Explanation of Solution

The emission of beta particle is resulted by due to conversion of neutron to electron and proton. From this only electron is emitted out. So, there is no electron captured form outside of nucleus.

Interpretation Introduction

(j)

Interpretation:

To analyse whether the given statement - For the purposes of determining atomic numbers in a nuclear equation, an electron is assumed to have a mass number of zero and atomic number of -1, is true or not.

Concept Introduction:

The VSEPR model is the model which is used for understanding the bond angles of atoms depending upon its electronegativity. VSEPR model is useful to predict bond angles occurred between atoms of a molecule. The bond angle of atom is a point where two atoms are joined together. The valence-shell electron-pair repulsion model is full form of VSEPR model.

Answer to Problem 9.18P

For the purposes of determining atomic numbers in a nuclear equation, an electron is assumed to have a mass number of zero and atomic number of -1. Thus, the statement is true.

Explanation of Solution

For the purposes of determining atomic numbers in a nuclear equation, an electron is assumed to have a mass number of zero and atomic number of -1.

Interpretation Introduction

(k)

Interpretation:

To analyse whether the given statement -The symbol of an alpha particle is $\text{H}\text{e}$ ,is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

The symbol of an alpha particle is $\text{H}\text{e}$.Thus, the statement is true.

Explanation of Solution

Alpha particle is a helium nucleus and has symbol of $\text{H}\text{e}$.

Interpretation Introduction

(l)

Interpretation:

To analyse whether the given statement - When a nucleus emits an alpha particle, the new nucleus has an atomic number two units higher and a mass number four units higher, is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When a nucleus emits an alpha particle, the new nucleus has an atomic number two units lower and a mass number four units higher. Thus, the statement is false.

Explanation of Solution

During the alpha emission, helium nucleus is emitted, and new nucleus is formed with atomic number decreased by two number and mass number increased by four numbers.

Interpretation Introduction

(m)

Interpretation:

To analyse whether the given statement - When uranium-238 ($U$) undergoes alpha emission, the new nucleus is thorium-234 ($T\text{H}$), is true or not.

Concept Introduction:

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When uranium-238 ($U$) undergoes alpha emission, the new nucleus is thorium-234 ($T\text{H}$). Thus, the statement is true.

Explanation of Solution

As uranium-238 undergoes alpha emission, the new nucleus contains atomic mass decreased by two numbers and mass number increased by four numbers resulting into thorium-234.

Interpretation Introduction

(n)

Interpretation:

To analyse whether the given statement - The symbol of a positron is $\beta$ ,is true or not.

Concept Introduction:

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

The symbol of a positron is $\text{e}$.Thus, the statement is false.

Explanation of Solution

Positron emission is emission of electron but positively charged and have symbol of $\text{e}$.

Interpretation Introduction

(o)

Interpretation:

To analyse whether the given statement - A positron is sometimes referrred to as a positive electron,is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

A positron is sometimes referrred to as a positive electron. Thus, the statement is true.

Explanation of Solution

A positron is an electron that is positively charged and referred as positive electron.

Interpretation Introduction

(p)

Interpretation:

To analyse whether the given statement - When a nucleus emits a positron, the new nucleus has the same mass number but an atomic number one unit lower, is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When a nucleus emits a positron, the new nucleus has the same mass number but an atomic number one unit lower.Thus, the statement is true.

Explanation of Solution

The positron is emitted because proton becomes neutron and comes out form nucleus. This reduces atomic number.

Interpretation Introduction

(q)

Interpretation:

To analyse whether the given statement - When carbon-11 ($\text{C}$) emits a positron, the new nuclues formed is boron-11 ($B$),is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When carbon-11 ($\text{C}$) emits a positron, the new nuclues formed is boron-11 ($B$).Thus, the statement is true.

Explanation of Solution

Due to positron emission, proton comes out from nucleus as neutron and there is a decreased one of atomic number. Carbon-11 has atomic number 6 which after positron emission converted into Boron-11 with atomic number of 5.

Interpretation Introduction

(r)

Interpretation:

To analyse whether the given statement - Alpha emission and positronemission both results in the formation of of a new nucleus with a lower atomic number,is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

Alpha emission and positronemission both results in the formation of of a new nucleus with a lower atomic number.Thus, the statement is true.

Explanation of Solution

In alpha emission two numbers and in positron emission one number of atomic numbers is decreased and results into new nucleus with a lower atomic number.

Interpretation Introduction

(s)

Interpretation:

To analyse whether the given statement - The symbol for gamma radiation is $\begin{array}{l}\gamma \end{array}$ ,is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

The symbol for gamma radiation is $\begin{array}{l}\gamma \end{array}$.Thus, the statement is true.

Explanation of Solution

The gamma radiation is decay in which nucleus gets stabilized from higher energy levels to lower energy levels and contain symbol of $\gamma$.

Interpretation Introduction

(t)

Interpretation:

To analyse whether the given statement - When a nucleus emits gamma radiation, the new nucleus formed has the same mass number and same atomic number,is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When a nucleus emits gamma radiation, the new nucleus formed has the same mass number and same atomic number.Thus, the statement is true.

Explanation of Solution

Gamma radiation occurs because of energy released from nucleus as it stabilizes from higher energy state to lower energy state and resulting into no transmutation in nucleus.

Interpretation Introduction

(u)

Interpretation:

To analyse whether the given statement- When a nucleus captures an extranuclear clectron, the new nucleus formed has the same atomic number but a mass number one unit lower,is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When a nucleus captures an extranuclear clectron, the new nucleus formed has the same mass number but atomic number one unit lower.Thus, the statement is false.

Explanation of Solution

In electron capture, there is absorption of electron from outside of nucleus and change occurs in number of atomic number with no effect in mass number.

Interpretation Introduction

(v)

Interpretation:

To analyse whether the given statement - When gallium-67 ($G\text{a}$) undergoes electron capture, the new nucleus formed is gemanium-67 ($G\text{e}$),is true or not.

Concept Introduction:

An element containing isotopes which are emitting radiations are known as radioactive isotopes. This can emit radiation because of instability its nuclei. Isotopes which are having balance numbers of protons and neutrons are stable, but the serious imbalance can lead to nuclear reaction. The emissions occur due to nuclear reactions are alpha emission, beta emission, positron emission, gamma emission and electron capture.

1. Alpha emission is an emission of helium nucleus (2 Protons and 2 neutrons) from the elements to stabilize the nucleus. This emission results into decrease by two in atomic number and increase by four in mass number.
2. Beta emission is an emission of beta particle as electron from nucleus of molecule. This emission results into increase in atomic number and no change in mass number.
3. Positron emission is an emission in electron with positive charge is emitted by nucleus of molecule. This emission results into decrease by one number in atomic number and no change in mass number.
4. Gamma radiation is only access energy from nucleus is emitted to stabilize nucleus of molecule. This emission results into no change in mass number and atomic number.
5. Electron capture- Electron capture occurring by absorption of electron in nucleus which reacts with proton to form neutron and in this reaction new nucleus have increase in atomic number and no change in mass number.

Answer to Problem 9.18P

When gallium-67 ($G\text{a}$) undergoes electron capture, the new nucleus formed is Zinc-67 ($Zn$).Thus, the statement is false.

Explanation of Solution

Extra electron is absorbed from outside in electron capture radiation. The gallium-67 undergoes electron capture and form a nucleus of Zinc-67 which has atomic number of 30 because of reduction of one number in atomic value.