1. What is another word for a cloud of dust and gas? 2. What do all stars begin as? 2. Stars form through a process called nuclear _____________. 3. What do stars turn into after they die? 4. Where did the heavy elements that make up Earth come from? 5. When light from a star is moving TOWARD the Earth, what color shift does it have? 6. When light from a star is moving away from the Earth, what color shift does it have? 7. The explosion of a red supergiant leads to a __________________________: 8. After one half-life, how much parent material will remain in a 600 gram sample of the radioactive isotope Carbon-12? 9. How old is the solar system? 10. The _____________ theory states that a rotating cloud collapsed under its own gravity to form the solar system, sun, and planets. 11. What is the Big Bang Theory? 12. Draw a diagram OR list the Earth's layers in the correct order. 13. How do scientists know that the Earth is made up of different layers? 14. Is the crust denser/ heavier compared to the core? Why or why not? 15. What layers are the Earth's mantle made of? 16. What are earthquakes caused by? 17. ________________ plate boundaries are when plates move apart. 18. __________ plate boundaries are when plates slide past eachother. 19. What are convection currents? Where are they located? 27. How do volcanoes occur? 28. List all of the Earth features that result from plate tectonics activity that we learned about. 29. What are tectonic plates? Where are they located? 30. Why do we say that water is polar? What does polarity mean in this regard? 31. Do polar substances dissolve in non-polar substances? 32. What is a real-life example of cohesion? What is a real-life example of adhesion? 33. What is the pH of water? 34. What is the formula for density? WHat is the density of a block weighing 20 grams and with a volume of 5 cm3? 35. What is the density of water? 36. liquid to gas= _________________________________ gas to liquid= __________________________________ 37. What are some examples of precipitation? 38. What are clouds mostly made of?