Astronomy Review partial Chp 6-7

If a hydrogen emission line appears at 656 nm in the laboratory, what can we say about a cloud of hydrogen gas, with an emission line at 680 nm?

• It is moving toward us.

• It is neither receding nor approaching us.

• It is receding away from us.

• There is not enough information to say anything about the cloud's motion.

Which of the following wavelength regions cannot be studied at all with telescopes on the ground?

• infrared

• x-rays

• radio

• both radio and x-rays

An electron in an atom can go from a lower energy level to a higher energy level if the atom:

• absorbs a photon of any wavelength.

• absorbs a photon of a specific wavelength.

• emits a photon of any wavelength.

• emits a photon of a specific wavelength.

• emits several photons of a specific wavelength.

Astronomers sometimes make use of "neutrino telescopes," which are typically located deep underground. What are neutrinos?

• a type of wave predicted to exist by Einstein's general theory of relativity

• a type of light-weight subatomic particle

• a very low-energy form of light

• a very high-energy form of light

Which of the following stars has the hottest surface temperature?

• the blue star

• the yellow star

• the orange star

• the red star

If a material is transparent, then it:

• absorbs light well.

• emits light well.

• scatters light well.

• reflects light well.

• transmits light well.

Spectra from neutral atoms compared with spectra from ionized atoms of the same element are:

• are slightly blueshifted.

• are slightly redshifted.

• are the same.

• have the same sets of spectral lines but different widths for those lines.

• have different sets of spectral lines.

A gold atom has an atomic number of 79 and an atomic mass number of 197. If it is neutral, how many protons, neutrons, and electrons does it have?

• 79 protons, 118 neutrons, 118 electrons

• 79 protons, 118 neutrons, 39 electrons

• 118 protons, 79 neutrons, 118 electrons

• 79 protons, 118 neutrons, 79 electrons

• 118 protons, 39 neutrons, 118 electrons

Which of the following is one important reason why most large astronomical telescopes are reflecting telescopes rather than refracting telescopes?

• Reflecting telescopes are taller than refracting telescopes.

• Reflecting telescopes take up less space than refracting telescopes.

• Reflecting telescopes have their heaviest component (the mirror) at the bottom rather than the top of the telescope's tube.

• For a mirror and lens of the same diameter, a mirror will collect more light.

If you want to see the image formed by a telescope, you should place your eye at the location of the telescope's

• primary mirror.

• Cassegrain.

• central hole in the primary mirror.

• secondary mirror.

• focus.