Which of the following nuclei is not "doubly magic"?

Question

Quizplus · Accepted Answer

A nucleus is considered "doubly magic" if both the number of protons and the number of neutrons are magic numbers. Magic numbers are certain numbers of protons or neutrons that correspond to a particularly stable configuration. The magic numbers for protons are 2, 8, 20, 28, 50, 82, and 114. The magic numbers for neutrons are 2, 8, 20, 28, 50, 82, and 126. Option D (¹²²Sn) has 50 protons (magic number) but 72 neutrons, which is not a magic number. Therefore, it is not "doubly magic". The other options have both the number of protons and neutrons as magic numbers, and are considered "doubly magic" nuclei.

Which of the Following Nuclei Is Not "Doubly Magic