science 16

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  1. nuclear fusion
    the process by which two or more small nuclei fuse to make a bigger nucleus.
  2. nuclear fission
    the process by which a large nucleaus is split into smaller nuclei
  3. critical mass
    the amount of isotope necessary to sustain a chain reaction
  4. absolute magnitude
    the brightness of a star corrected for distance on a scale of -8 to +19 the smaller the number the brighter the star
  5. apparent magnitude
    the brightness of a star as seen in the night sky. the smaller the number the brighter the star
  6. light year
    the distance light could travel along a straight line in one year
  7. galaxy
    a large ensemble of stars all interacting through the gravitational force orbiting around a common center
  8. from inside out name the 4 regions of the sun
    core  , raidiative zone, convection zone, photosphere.
  9. how does the sun get its power? in what region does this process occur?
    nuclear fusion that occurs in the core
  10. what part of the sun do we see?
  11. a251 Cf nucleus is bombarded with a neutron. it breaks down into a 124Sn nucleaus, a 120Cd nucleaus and seven nuetrons. is this nuclear fission or nuclear fusion?
    nuclear fission
  12. two 4He nuclei collide and turn into a 7Be nucleaus and one neutron. is this nuclear fusion or nuclear fission.
    nuclear fusion
  13. for both the nuclear fusion that occurs in the sun and the nuclea fission that occurs in a nuclear power plant what can we say bout the mass of the starting materials compared to the mass of whats made in the end.
    its bigger **In both processes, mass in converted into energy.  The mass of the starting material is larger than the mass of the materials the process makes.
  14. why is it impossible for a nuclear power plant to have a nuclear explosion
    because the only way it would explode is if there were a chain reaction and those only happen if there are enough large nuclei present
  15. why is nuclear fusion considered a better option for energy production than nuclear fission?
    because there are no radioactive byproducts, there is no chance of meltdown, and the starting materials are cheap
  16. if nuclear fusion is better why don't we use it?
    we haven't mastered the technology to make it economically feasible
  17. graph
    a. red giants    b. main sequence   c. super giants   d. white dwarfs
  18. which of the stars in number 11 is most like our sun?
    main sequence stars
  19. order the four stars in 11 in terms of increasing size
    white dwarfs, main sequence, red giants , super giants
  20. order the four stars in terms of brightness
    white drawfs, main sequence, red gaints, super giants
  21. which of the stars is the coolest
    red giants
  22. What similarity exists between novas, supernovas, and pulsating variables?
    They are all variable star types. Thus, their brightness changes radically with time.
  23.  What is the big difference between novas, supernovas, and pulsating variables?
    their lifespan  ** Pulsating stars last a ling time, supernovas exist briefly, and novas are somewhere in between.
  24.  What most likely formed the crab nebula?
  25.  What are the two methods for measuring the distance from earth to a star? Which of the is the most accurate? Which can be used to measure long distances?
     Parallax method, and the apparent magnitude method. Parallax. Apparent magnitude.
  26. Why are Cepheid variables so important for measuring long distances in the universe?
    Cepheid variables are important for measuring long distances because them seem to have a relationship between their period and their magnitude.  That allows them to be used in apparent magnitude method for measuring long distances in the universe.
  27. What are the four basic types of galaxies? To which type does the Milky Way belong?
    Spiral, elliptical, lenticular, and irregular. Spiral galaxy.
  28.  Fill in the blanks: Stars group together to form ..., which group together to from ..., which group together to from ..., some of which group together to form
    Galaxies, groups, clusters, superclusters.
  29. For the first three answers you gave in #22, give the names that apply to those in which earth's solar system belongs.
    Milky Way, Local Group, Virgo Cluster.
  30. Why do most astronomers believe the universe is expanding?
    Because the light from nearly every galaxy experiences a red shift before it reaches the earth, and the red shift increases the farther the galaxy is from the earth.
  31. If the universe is expanding, does the geometry of the expansion matter? If so, why?
    Yes. Because, the theories that can be developed for the formation of the universe depend on that initial assumption.
Card Set:
science 16
2015-06-11 17:56:36

cience 16
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