The Disks of Spiral Galaxies Appear Blue Because

question 74

Multiple Choice

The disks of spiral galaxies appear blue because:

• A) they are moving toward us
• B) they contain a relatively high concentration of low-mass stars
• C) they contain active regions of star formation
• D) they contain more metals that, when ionized, emit blue light
• E) stars collide with each other frequently in these dense regions and explode as Type I supernovae

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Definitions:

Celsius

A scale and unit of measurement for temperature where 0 degrees is the freezing point and 100 degrees is the boiling point of water under standard atmospheric conditions.

Body Temperature

The measure of the body's ability to generate and get rid of heat, essential for the proper function of enzymes and bodily processes.

Boiling

The rapid vaporization of a liquid when it is heated to its boiling point, the temperature at which it changes phase from liquid to gas.

Fahrenheit

A scale for measuring temperature where 32°F is the point at which water freezes and 212°F is the point at which it boils under normal atmospheric pressure.