For Balmer Series Lines to Show Up Strongly in Absorption

question 211

Multiple Choice

For Balmer series lines to show up strongly in absorption in stellar spectra,significant numbers of hydrogen atoms have to have electrons in the n = 2 energy level.What then does the appearance of these lines in a stellar spectrum tell us about the temperature of the star's surface?

• A) The appearance of the lines tells us very little about the temperature because hydrogen gas will show significant Balmer absorption, whatever the surface temperature.
• B) The temperature must be high enough to ionize the hydrogen atoms by collision in order that they can absorb from this level.
• C) The temperature must be reasonably low so that no atoms will have electrons excited beyond this energy level (e.g., to n = 3).
• D) The temperature must be reasonably high to excite the electrons to this level by collisions, but not high enough to ionize the atoms.

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Movements

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Pressure

The force exerted on a surface area divided by the total area on which the force is exerted; often related to gases or liquids in scientific contexts.

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Sensory receptors located in the inner ear that are responsible for providing the brain with information about motion, head position, and spatial orientation.

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The innermost part of the ear, containing the cochlea, vestibule, and semicircular canals, responsible for sound detection and balance.