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Home Q & A Board Science-Related Homework Help Physics
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staedtler staedtler
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7 years ago
What radiation ionizes the hydrogen in an emission nebula (H II region)?
A)   Ultraviolet radiation from O and B stars
B)   X rays from the coronas of solar-type stars
C)   Infrared radiation from pre–main-sequence stars
D)   Gamma rays from neutron stars
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Discovering the Universe

Discovering the Universe


Edition: 7th
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discovererdiscoverer
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staedtler Author
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7 years ago
Grinning Face Exactly what I needed
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4 years ago
thank you
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