In earlier times, the challenge of alpha-particle barrier penetration was a notable concern in the domain of classical mechanics. The application of quantum mechanics to this problem not only aids in its comprehension but also provides insights into various questions, including the variation of alpha energy with half-life, which is a key aspect of the Geiger-Nuttall rule and can be explained through quantum mechanics.  Alpha decay exemplifies a practical issue that directly relates to the theoretical concepts of potential wells and barriers introduced in the foundational stages of quantum mechanics education. A comprehensive grasp of this theory is essential for tackling more intricate problems within the discipline. This text provides an in-depth exploration of the alpha-decay issue, emphasizing the limitations of classical methods in examining the relationship between decay energy and half-life, while also demonstrating how quantum mechanics effectively addresses these challenges. Furthermore, the book offers a detailed analysis of the energetics involved in alpha decay, thereby enhancing students' comprehension of the subject. A solid understanding of alpha-decay energetics lays the groundwork for a more straightforward grasp of beta-decay energetics. The focus of this book is exclusively on transitions from ground state to ground state for even-even nuclei (even atomic number and even neutron number). Calculations related to odd-odd, even-odd, and odd-even nuclei are not included, as they fall outside the intended scope of this work. However, future editions may consider incorporating this topic as an additional feature.