"Dark Matter" Is Matter That Gives Out No Observable Radiation

question 441

Multiple Choice

"Dark matter" is matter that gives out no observable radiation and is detected by its gravitational interaction alone.Some of our evidence for dark matter comes from all of the following EXCEPT ONE.Which is the exception?

• A) separation of visible and dark matter in collisions of galaxy clusters
• B) emission from hot intergalactic gas in galaxy clusters
• C) gravitational lensing by unseen objects
• D) insufficient visible mass to bind galaxy clusters gravitationally

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Definitions:

Concentration

Concentration refers to the amount of a substance per defined space; it is a measure of how much of a solute is dissolved in a specific amount of solvent.

Exothermic

Describes a chemical reaction that releases heat into its surroundings.

ΔS°

The standard entropy change of a system, measuring the change in disorder or randomness during a chemical process under standard conditions.

ΔH°

Denotes the standard enthalpy change of a reaction, measured under standard conditions (1 atm, 298.15 K).