# What is the half-life of Uranium-238?

Feb 6, 2014

#### Answer:

The half-life of uranium-238 is 4.468 billion years.

#### Explanation:

Scientists estimate the age of the Earth as 4.54 billion years, plus or minus about fifty million years.

That means that about 49 % of all the uranium-238 that existed when the earth was formed is still present.