Chapter 20, Problem 79E

Interpretation Introduction

Interpretation: The nuclear equation for the most likely mode of decay for each of the given unstable nuclide is to be written.

Concept Introduction: Type of radioactivity can be explained by nuclear stability after the decay, which is determined by the ratio of neutrons to protons. The $\frac{N}{Z}$ ratio for a stable nucleus with an atomic number around 40 is 1.25 and for a stable nucleus with an atomic number above 83 is 1.5, where N is the number of neutrons and Z is the atomic number.

There are two possibilities:

When $\frac{N}{Z}$ is too high, the nucleus tends to have beta decay as there are more neutrons than protons and they tend to convert to protons.

However, when $\frac{N}{Z}$ is too low, the nucleus tends to undergo positron emission or electron capture as there are more number of protons and they tend to convert to neutrons.