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Home Q & A Board Science-Related Homework Help Physics
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bugg bugg
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11 years ago
A) Molecules such as NH3 and CH4, which contribute to giant molecular clouds
B) UV light that photoionizes hydrogen. This hydrogen, upon recombination, produces the red balmer light by which we see interstellar emissions nebulae.
C) Rotational motion from the original star, which serves to concentrate interstellar matter into new stars and planetary systems.
D) The nuclei of moderately heavy elements, major components of planets such as our own

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11 years ago Edited: 11 years ago, bio_man
Planetary nebulae play a crucial role in the chemical evolution of the galaxy, returning material to the interstellar medium that has been enriched in heavy elements and other products of nucleosynthesis (such as carbon, nitrogen, oxygen and calcium). In more distant galaxies, planetary nebulae may be the only objects that can be resolved to yield useful information about chemical abundances.
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