1. What does the layer of iridium in the rock record tell about the demise of dinosaurs? 2. Fossils of ancient sea creatures have been found on modern mountains. Explain how this is possible. 3. Smash...

1. What does the layer of iridium in the rock record tell about the demise of dinosaurs?

2. Fossils of ancient sea creatures have been found on modern mountains. Explain how this is possible.

3. Smash a few salt cubes and then look at them carefully again. What you’ll see are smaller salt cubes. Explain why salt breaks into cubes in terms of the property of cleavage.