8th Unit 2 Puzzle 2 --- Name:

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Across
  1. 4. the Sun and all the objects that revolve around the Sun as a result of gravity.
  2. 7. dwarfs less massive and much smaller in size than the Sun
  3. 8. stage in a star's development when the inner helium core contracts while the outer layers of hydrogen expand, producing a very large red star.
  4. 9. a process in which low-mass nuclei (ex. H or He) combine to form a heavier and more stable nucleus, releasing an enormous amount of energy; most of the Sun's energy comes from nuclear fusion.
  5. 11. the measure of the average kinetic energy of the particles in matter; a physical property of matter.
  6. 12. the ability to do work
Down
  1. 1. scientists who study the universe beyond Earth, such as the universe, galaxies, and stars
  2. 2. cloud of dust and gas where stars form in space.
  3. 3. a very large group of stars held together by gravity; few million to a few billion stars
  4. 5. an enormous star that is near the end of its life
  5. 6. stars that fuse hydrogen into helium for energy
  6. 10. the center of an atom, made of protons and neutrons