Chapter 18, Problem 13QRT

(a)

Interpretation Introduction

Interpretation:

The process for conversion of Uranium-238 to thorium-234 has to be given.

Concept Introduction:

If the reaction occurs in the nucleus of an atom then it is known as nuclear reaction.  These reactions are not considered as ordinary chemical reactions because the electrons do not take part in reaction while the particle inside the nucleus does.  Isotope and nuclide are almost similar terms.  Isotopes refer to the same element that has different mass number while nuclide refers to atoms of same or different elements with specific atomic number and mass number.

This nuclear reaction can be represented by nuclear equation.  This is not a normal chemical equation.  Nuclear equation considers the mass number and atomic number of the reactants and products.  Unstable nucleus tends to emit radiation spontaneously.  During this process the nuclide is transformed into nuclide of another element.  Parent nuclide is the one which undergoes the radioactive decay.  Daughter nuclide is the one that is formed from parent nuclide after radioactive decay.

The radioactive decay can take place by emission of alpha particle, beta particle or gamma ray emission.  Alpha particle decay is a process in which an alpha particle is emitted.  This results in the formation of nuclide of different element that has atomic number that is 2 less and mass number that is 4 less than the original nucleus.  Beta particle decay is a process in which a beta particle is emitted.  This produces a nuclide of different element similar to that of alpha particle decay.  The mass number is same as that of parent nuclide while the atomic number increases by 1 unit.  Gamma ray emission is a process in which the unstable nucleus emits gamma ray.  This occurs along with alpha or beta particle emission.  The gamma rays are not shown in the nuclear equation because they do not affect balancing the nuclear equation.

Apart from alpha, beta, or gamma radiation, positron emission also takes place.  This is a positively charged electron.  Positron emission results in the decrease in atomic number of the formed nuclide.  There is no change in mass number.

(b)

Interpretation Introduction

Interpretation:

The process for conversion of Iodine-131 to xenon-131 has to be given.

Concept Introduction:

Refer part (a).

(c)

Interpretation Introduction

Interpretation:

The process for conversion of Nitrogen-13 to carbon-13 has to be given.

Concept Introduction:

Refer part (a).

(d)

Interpretation Introduction

Interpretation:

The process for conversion of Bismuth-214 to polonium-214 has to be given.

Concept Introduction:

Refer part (a).