context: Uranium is not highly radioactive. The two most important isotopes are 235U and 238U. Also found in nature is a small amount of 234U, which is the result of the breakdown of 238U. All three isotopes decay through alpha radiation. Industrially, the most important isotope is 235U, which is used as nuclear fuel. 238U is the longest-lived uranium isotope with a half-life of 4.468 billion years. [3]
question: What is the Half Life of Uranium?
answers.text: 238U is the longest-lived uranium isotope with a half-life of 4.468 billion years