Because a radioactive form of argon is produced by decay of a naturally occurring radioactivepotassium isotope, it can be used to date rocks and samples more than 100,000 years old.
因为它是稀有天然放射性同位素钾衰变而产生的,所以可以用来测定十万年以上的岩石年龄和采样。
2
The ingestion of potassium iodide is an established method to prevent the accumulation of radioactive iodine in the thyroid.