Few People Today Even Know That the Milky Way Is

question 54

Multiple Choice

Few people today even know that the Milky Way is a spiral arm of our galaxy, containing such a dense cluster of stars that in the past it appeared not as individual points of light but as a splash of light across the night sky. Why is it no longer visible this way?

• A) the greenhouse effect
• B) light pollution
• C) global dimming
• D) air pollution
• E) the breaking of the Hubble telescope on the International Space Station

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Definitions:

Chiral

Describes a molecule that has a non-superimposable mirror image, often leading to molecules with distinct left-handed (S) and right-handed (R) configurations.

Achiral

Describing a molecule that is superimposable on its mirror image, indicating it has no handedness or enantiomers.

Enantiomers

Molecules that are mirror images of each other but cannot be superimposed on each other, much like left and right hands.

Diastereomers

Stereoisomers that are not mirror images of each other and have different physical and chemical properties.