0 a chemical element that is a soft, silver-white metal and is radioactive -- 锕
Researchers are testing the actinium. 研究者正在测试锕。
Thorium decays into a radium isotope, and then into actinium, which has a 10-day half-life.
Various alternative processes have been proposed for making actinium.
Most of the chemistry has been observed only for the first three members of the group; chemical properties of both actinium and especially lawrencium are not well-characterized.
Ac, the radiation from the actinium and its decay products might induce new mutations.
Several isotopes of bismuth with short half-lives occur within the radioactive disintegration chains of actinium, radium, and thorium, and more have been synthesized experimentally.
Actinium has similar chemical properties as lanthanum and other lanthanides, and therefore these elements are difficult to separate when extracting from uranium ores.
Actinium is mostly present in uranium-containing, but also in other minerals, though in much smaller quantities.
