Exam 18: The Interstellar Medium: Gas and Dust Among the Stars

The "Local Bubble" was probably created by:

What effect do even thin clouds of dust have on light passing through them?

Contrast the chemical composition of interstellar gas with that of interstellar dust.

H II regions are usually found isolated from other stars or types of nebulae.

There is as much mass in the voids between the stars as in the stars themselves.

The H I regions are mapped by the radiation created when an electron flips its spin.

We look toward a cool star. How can we determine that there is an interstellar dust cloudbetween us and the star?

Most molecules found in the giant molecular clouds are based on silicon.

The "Local Bubble" was probably created by a nearby supernova in the distant past.

Unlike atoms, molecules can:

Which statement is true about the interstellar medium?

Molecular hydrogen is most effectively detected by ________ observations.

Spectra of stars often show narrow absorption lines from interstellar matter. What type ofinterstellar matter produces these?

The density of interstellar dust is very low, yet it still blocks starlight because:

Interstellar matter is distributed very evenly through the galaxy.

Molecular cloud complexes are:

The dark dust clouds can be explored better with infrared than with visible light.

An emission nebula appears primarily ________ in color, due to ionized hydrogen.

Most interstellar clouds are:

Molecular clouds can be detected by radio observations of molecular hydrogen.