Exam 2 Study Guide Chapter 16, Star birth 1. Where are stars born? 2. In percent mass, what does the interstellar medium of our galaxy consists of? 70% hydrogen, 28% helium, 2% heavier elements. 3. What is the most abundant molecule in molecular clouds? Molecular hydrogen 4. What is interstellar reddening? Dust grains block the bluer wavelength causing reddening on the edges of molecular clouds. 5. What part of the light spectrum is best to view stars within a molecular cloud? 6. What prevents the pressure from increasing as a cloud contracts due to its gravity? 7.
How was the first generation of stars different from stars born today? 8. What causes the temperature to rise to the point of nuclear fusion inside a molecular cloud? 9. What happens to the rotation of a molecular cloud as it collapses to form a star? 10. At what point does a protostar become a true star? Chapter 14, Our star – the sun 1. Why does the sun shine? 2. What is the power source of the sun? What is hydrogen being converted into? 3. What do we mean when we say that the Sun is in gravitational equilibrium? 4. Lists the “layers” of the Sun in the correct order?
What are the physical characteristics of each layer? 5. What are sunspots? How do they form? Chapter 17, Star Stuff 1. Where did the elements heavier than hydrogen and helium come from? 2. Why does a star grow larger after it exhausts its core hydrogen? 3. What does helium fusion produce? 4. Which element has the lowest mass per nuclear particle and therefore cannot release energy by either fusion or fission? 5. What is a helium flash? Why does it occur and how does it affect the star? How is it represented on the H. R. diagram? 6. What is a planetary nebula? a.
From what type of stars are planetary nebula formed and how are they formed? b. How are planetary nebulas represented on the H. R. diagram? c. What happens to a stars core after a planetary nebula occurs? 7. What is a carbon star? From what type of stars are carbon stars formed from? Why are carbon stars important for life on earth? 8. What is the CNO cycle? In what type of stars does the CNO cycle occur? How does the CNO cycle differ from the proton- proton chain reaction? 9. What happens when the gravity of a massive star is able to overcome electron degeneracy pressure?
What happens when it overcomes neutron degeneracy pressure? Chapter 18 The Bizarre Stellar Graveyard What is the upper limit of mass that a white dwarf can have? What happens when the mass exceeds that limit? How does the size of a . 8 solar mass star compare to that of a 1. 2 solar mass star? What is a pulsar? Define what a black hole is? How does a star form into a black hole Chapter 8, Our Solar System What is the solar nebula? What was it made of and where did it come from? List the four categories of materials in the solar nebula by their condensation properties and abundance.
Which ingredients are present in terrestrial planets? In Jovian planets? What happened during the accretion phase of the early solar system? What was the frost line in the solar nebula? Explain how temperature differences led to the formation of two distinct types of planets. Why are the inner planets made of denser material than the outer planets? What is the origin of the large moons found around the Jovian planets? What are asteroids and comets? Where does most of the water we drink originate from?