Read the Assertion and Reason below and choose the correct option. — Nuclear Chemistry and Radioactivity Chemistry Question

💡 Solution & Explanation

${}_{13}^{30}\text{Al}$ has 13 protons and 17 neutrons (odd-odd), making it generally unstable. ${}_{20}^{40}\text{Ca}$ has 20 protons and 20 neutrons (even-even), which is highly stable (doubly magic). Both statements are true. However, Statement II only explains why $\text{Al}^{30}$ is unstable; it does not fully explain the relative comparison since it doesn't mention the stability of even-even nuclei. Thus, it is not the complete/direct explanation. Therefore, correct answer is B.