ウラン-238は、既知のすべての要素の中で最も長い半減期を持っています。半減期は約45億年で、これは地球自体の推定年齢よりもはるかに長いです。これは、純粋なウラン238のサンプルを測定する場合、最初にサンプルが最初に生成されたときと同じ量を見つける可能性が高いことを意味します。これにより、地質学的特徴と私たちの惑星の歴史を理解するのに非常に役立ちます！
Uranium-238 has the longest half-life of all the known elements. It has a half-life of approximately 4.5 billion years, which is much longer than the estimated age of the Earth itself. This means that if you were to measure a sample of pure uranium-238, you would likely still find the same amount of it as when the sample was first produced in the first place. This makes it incredibly useful for dating geological features and understanding the history of our planet!