Chapter 11, Problem 11.49EP

Interpretation Introduction

Interpretation:

When Rn-222 undergoes alpha decay consecutively, the nucleus A and nucleus B formed has to be identified.

Concept Introduction:

Radioactive nuclides undergo disintegration by emission of radiation.  All the radioactive nuclide do not undergo the decay at a same rate.  Some decay rapidly and others decay very slowly.  The nuclear stability can be quantitatively expressed by using the half-life.

The radioactive decay occurs till a stable nucleus is formed.  Radioactive series is a decay process that occurs in series which begins with the long-lived radionuclide and ends up with nuclide having less atomic number that is stable.

The radioactive decay can take place by alpha emission, beta emission or gamma ray emission.  Alpha emission 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 emission 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 emission.  The gamma rays are not shown in the nuclear equation because they do not affect balancing the nuclear equation.