Astronomy quiz question: interstellar gas and dust in the Milky Way

Astronomy 210 Quiz 7, fall semester 2015
Cuesta College, San Luis Obispo, CA

Interstellar gas and dust in the Milky Way prevents most of its __________ from being visible from Earth.
(A) stars.
(B) dark matter.
(C) radio waves.
(D) neighboring galaxies.

Correct answer (highlight to unhide): (A)

Interstellar gas and dust blocks visible light from stars, while typically not affecting longer wavelength forms of light such as radio waves. Dark matter is not visible already, and clear views of our neighboring galaxies can be seen above and below the gas and dust in the disk of the Milky Way.

Section 70158
Exam code: quiz07srrH
(A) : 32 students
(B) : 1 student
(C) : 0 students
(D) : 6 students

Success level: 83% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.62

Section 70160
Exam code: quiz07nM0r
(A) : 18 students
(B) : 1 student
(C) : 1 student
(D) : 6 students

Success level: 75% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64