Very Hot Stars Have Weak Hydrogen Spectral Lines

question 24

Multiple Choice

Very hot stars have weak hydrogen spectral lines. Why is this?

• A) These stars contain very little hydrogen.
• B) The hydrogen in the atmospheres of these stars is combined into molecules, and these have different spectra.
• C) The electrons in the hydrogen atoms in these stars are all in their lowest energy levels, and they cannot radiate from these levels.
• D) The hydrogen atoms in these stars are mostly ionized and hence cannot radiate.

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