Chapter 24, Problem 24.144P

(a)

Interpretation Introduction

Interpretation : The symbol of isotope should be comprehended for the given nuclei where nucleus 1 is stable and 2,3 are unstable.

  

Concept Introduction : Isotopes are elements with the same atomic number but a different mass number. Since the atomic number is the same, so the number of protons and electrons must be the same. The different mass number indicates the difference in the number of neutrons of the isotopes.

Hence, isotopes of an element have the same number of protons but different numbers of neutrons.

(b)

Interpretation Introduction

Interpretation : The most likely mode of decay of nuclei $2$ ( $\text{X}$ ) and $3$ ( $\text{X}$ ) should be interpreted for the given nuclei.

  

Concept Introduction : Isotopes are elements with the same atomic number but a different mass number. Since the atomic number is the same so the number of protons and electrons must be the same. The different mass number indicates the difference in the number of neutrons of the isotopes.

Hence, isotopes of an element have the same number of protons but a different number of neutrons.