100 Points! 8 Questions! Thank you(: (No Links) 1. Select the correct answer from the list.
To form a nebula, pulls matter together or causes
Blank One:
A. Gravity
B. Pressure
C. Heat
Blank Two:
A. An explosion
B. Infrared light emission
C. Pressure change

2. How do emission and reflection nebulae differ?
A. The presence of young stars
B. Hard line edges
C. interactions with light
D. contain remnants of starts

3. Select the correct answer from the list.
Astronomers think that most galaxies are centered by a which exerts ___ that binds the galaxy together.
Blank 1;
A. Nebula
B. Massive Star
C. Black Hole
D. Large Planet
Blank 2:
A. Centripetal force
B. Centrifugal Force
C. Gravitational Pull
D. Magnetic Pull

4. Which description best summarizes the steps that take place during black hole formation, in the correct order?
A. Supernova explodes a massive star; remaining core expands; nuclear reactions diminish the effects of gravity.
B. Supernova triggers fusion reactions; massive star implodes due to extreme radiation; volume and mass of star increase rapidly.
C. A small star gains mass through fusion reactions; core of star collapses; increased radiation triggers a supernova
D. A massive star depletes its nuclear fuel; gravity overpowers the star; supernova occurs; core of star collapses

5. Where could scientists look to observe a black hole?
A. The center of the sun
B. The solar system asteroid belt
C. The edge of the solar system
D. the center of the milky way

6. What is the main challenge astronomers face when trying to directly detect black holes?
A. Black holes trap all light
B. Black holes are too small
C. Black holes are empty
D. Black holes are too black

7. Which statement best describes the galaxies closest to the Milky Way?
A. These galaxies consist of mostly old stars
B. These galaxies are all identified as spiral
C. these galaxies include irregular, spiral, and elliptical types
D. These galaxies are independent of an unaffected by the Milky Way's gravitational pull

8. Which of these characteristics of a star make it most likely to become a black hole? Select the two correct answers.
A. Its mass is equal to that of the sun
B. It is dying
C. Its mass is greater than 20 times the mass of the sun
D. It has an abundant supplh of hydrogen