2. Objectives
Lesson Objectives
- Know that geologists and paleontologists use evidence to determine the history of Earth and life on Earth.
- Know that geologists and paleontologists measure the radioactivity in certain rocks to determine the age of the earth and fossils.
- Know that the earth is between four and five billion years old.
- Know that scientists need to know what the environment (what chemicals were around, the temperature, etc.) was like on Earth billions of years ago to know how life formed.
CK-12 Foundation, Biology. http://creativecommons.org/licenses/by-nc-sa/3.0/