This radioactive form of nitrogen does not occur in nature.

氮的这种放射性形式在自然界中不会产生。

youdao

Some elements such as uranium, commonly used as fuel in nuclear power plants, are always radioactive; there is no nonradioactive form of them that naturally occurs in nature.

一些如铀一般的元素，通常在核电厂用作核燃料，都是有放射性的；这些元素由于自身的性质是没有无放射性状态的。

youdao

The exact effect will depend on the nature and the amount of radioactive material that have been ingested.

确切影响将取决于放射性物质的性质和摄入量。

youdao

In view of the radioactive nature of thorium, a hazard is posed from waste produced in the processing of rare earth oxides, which contains it.

FORBES: Rare Earth Elements And Thorium Power