When excited electrons decay to ground state, hydrogen emits along distinctive line near the visible red. An astronomer observes what appear to be hydrogen emission lines from a distant star but they are in the infrared spectral band
She concludes ________.
A) the star's hydrogen emission must be being absorbed by water in the atmosphere, which then re-emits in the infrared
B) her instrument needs to be recalibrated
C) the star must be moving very fast toward Earth
D) the star must be moving very fast away from Earth
D
You might also like to view...
?Match the term with the correct description.
A. ?the world's largest ecological restoration project B. ?largest area of coastal wetlands in the lower 48 states C. ?ecosystem service that reduces flooding by storing storm water D. ?has lost 92% of its original coastal wetlands E. ?replacing each area of destroyed wetland with twice the same area of restored, enhanced, or created wetland
Which of the following objects would be best at scattering light?
A. A B. B C. C D. D
The igneous feature shown in this figure is a
A) dike.
B) sill.
C) volcanic neck.
D) laccolith.
What do the terms oligotrophic, mesotrophic, and eutrophic refer to?
a. nutrient levels in lakes b. severity of catastrophic events in nature c. depth of groundwater resources d. types of consumptive water use e. classes of groundwater based on origin