Since the unstable nuclei exist between actinides, including thorium and stable nuclei like lead and bismuth, explosive events such as supernovae are required to produce actinides.
自不稳定核之间存在着锕系元素，包括钍和稳定核像灌了铅，铋，爆炸性事件，如超需出示锕。
2
The crust granites have higher lead isotope ratios and are richer in uranium lead but poorer in thoriumlead.