| 词条 | protium |
| 释义 | protium isotope isotope of hydrogen (q.v.) with atomic weight of approximately 1; its nucleus consists of only one proton. Ordinary hydrogen is made up almost entirely of protium. |
| 随便看 |
百科全书收录100133条中英文百科知识，基本涵盖了大多数领域的百科知识，是一部内容开放、自由的电子版百科全书。