The oldest rock formation identified on Earth is found on the shoreline of Hudson Bay in Canada. This rock formed 4.28 billion years ago. What information does a scientist need to more accurately determine the age of a rock?

The amount of each radioactive element present in the rock.

The percentage of each mineral that makes up the rock.

The thickness of younger rock layers that cover the rock.

The amount of weathering present on the surface of the rock.

The correct answer is:

The amount of each radioactive element present in the rock.