The actual age of rocks can be determined by radioactive dating.

a. True

b. False

a. True

Explanation:

The absolute age of rocks can be determined in two ways: by fossil content or by radioactive dating, which uses the natural radioactivity of rocks. If the rock contains fossils, its age will be the age of those fossils. This is very simple, but it is a method with huge limitations. Not every rock contains fossils; the igneous, for example, never have them. And even when the rock contains remains or traces of animals or plants, they can be difficult to obtain.

When molten rock cools to form what we call igneous rocks, radioactive atoms are trapped inside. Later they decay at a predictable rate. By measuring the number of unstable atoms remaining in a rock and comparing it to the number of stable atoms in that rock, scientists can estimate how long it has been since the rock was formed by radioactive dating.