| 释义 |
> as lemmasuranium-238 uranium-238 n. the common naturally-occurring isotope of uranium, of mass number 238.Uranium-238 forms about 99.3 per cent of natural uranium. Unlike uranium-235, it is unable to sustain a nuclear chain reaction, making it unsuitable for use in nuclear power or nuclear weapons. However, the isotope plutonium-239, which is fissile, can be produced by bombarding uranium-238 with low-energy neutrons.< |