Question : Dark-line (absorption) spectra can be used to identify the present in stars : 2147176
69) Dark-line (absorption) spectra can be used to identify the ________ present in stars.
70) In the case of light, when a source is moving away, its light appears ________ than it actually is.
71) Galileo ________ telescopes.
A) did his work before the invention of
B) rarely used
C) built the first
D) benefited from and for his observations came to almost exclusively use
72) Sir Isaac Newton built and used ________ telescopes.
73) All of the world's largest telescopes are of the ________ type.
74) Radio telescopes have an advantage over optical telescopes in that they can be used ________.
A) during daylight hours
B) to detect visual imagery of pulsars
C) in all four seasons
D) to detect very short wave radiation
75) Radio telescopes are generally ________ than are optical telescopes.
A) much simpler
B) smoother in surface
C) much larger in size
D) more precise (higher resolution)
76) Sunspots appear dark because they are ________ than the surrounding solar surface.
B) more energized
C) less ionized
D) much closer to the Sun's core
77) The Sun's energy results from the conversion of ________ nuclei into helium nuclei.
78) The Sun is considered a(n) ________ star.