n.[化]钍（符号Th；原子序90）

Marie found another called thorium. 玛丽发现了另一种物质，叫钍。

A radioactive isotope of thorium with mass number228. 射钍钍的放射性同位，质量数为

This is clearly confirmed by the detection of thorium. 这显然证实了检测钍.

They recognized that in a thorium province Pb208 would present complications. 他们承认，含钍区内的Pb208会产生干扰。

Followed by the slow decomposition of uranium to another element thorium. 铀元素随后缓慢分解为另一种元素钍。