Question

Explain what the term half-life means and how knowing the half-life of an element can help a geologist establish the age of a rock or fossil.

Answer 1

Half-life means how much time that an element breaks down and decays into another element. [ Observing how many half-lives a rock has went through can tell scientist how old that rock is.

Answer 2

The half-life is defined as the time required for any specific property to reduce to half the original concentration.

Geologists use the half-life of the radioactive elements to determine the age of the rock or fossil.

The half-life a radioactive element refers to the time taken by a radioactive element in order to reduce its radioactivity to half of its original value.

Few isotopes have half-lives of billion years. For example, uranium-238 has a half-life of 4.46 billion years.

It enables the geologists to date the rock between 1 million and 4.5 billion years.