原子核2 https://hirakawatblog.com/%e7%89%a9%e7%90%86%e3%82%84%e5%8c%96%e5%ad%a6%e3%82%92%e7%bf%92%e3%81%86%e4%ba%ba%e5%bf%85%e8%a6%8b%ef%bc%81%e5%8e%9f%e5%ad%90%e6%a0%b8%e3%81%ae%e6%a7%8b%e9%80%a0%e3%82%92%e7%ab%8b%e4%bd%93%e7%9a%84/%e5%8e%9f%e5%ad%90%e6%a0%b8%ef%bc%92