isotopic isomer

例句：

1. 1.The isotopic composition of the sample is important for understanding its origin.
   样本的同位素组成对于理解其来源至关重要。
2. 2.Scientists are studying the isotopic ratios in rocks to determine their age.
   科学家们正在研究岩石中的同位素比例，以确定其年龄。
3. 3. The isotopic analysis of the water samples revealed that they were not from the same source.
   对水样进行同位素分析显示它们并非来自同一来源。