Problem 2
List the three major layers of Earth. Which is/are composed of rock, which is/are metallic? Which is the largest; which is the thinnest?
Problem 8
Define a system and explain why a systems approach is useful in Earth Science.
Problem 10
How old is Earth? When did life first evolve? How long have humans and their direct ancestors been on this planet?
Problem 13
Briefly outline the magnitude of human impact on the planet.
