Which characteristic of potassium makes it useful for dating rocks?

it has a long half-life.
it decays at an unknown rate.
it produces lead as it breaks down.
it can be used to date all types of rock.

It has a long half-life.

Explanation:

It's very useful to date rocks because its very long half-life allows to measure the age of rocks that are over 100,000 years old, which is about the double of the maximum age for which the carbon is used.

Because of its properties, it is a very useful tool to able to determine the age of rocks and fossils for example.

It has a long half-life. Explanation: It's very useful to date rocks because its very long half-life allows to measure the age of rocks that are over 100,000 years old, which is about the double of the maximum age for which the carbon is used.