What Prevents a Brown Dwarf from Undergoing Nuclear Fusion

question 4

Multiple Choice

What prevents a brown dwarf from undergoing nuclear fusion?

• A)Degeneracy pressure halts the contraction of a protostar so the core never becomes hot or dense enough for nuclear fusion.
• B)There is not enough mass to maintain nuclear reactions in a self-sustaining way.
• C)The surface temperature never rises high enough for the radiation to be trapped and heat their interior to the temperatures required for nuclear fusion.
• D)Radiation pressure halts the contraction of a protostar so the core never becomes hot or dense enough for nuclear fusion.
• E)There are too many heavy elements and not enough hydrogen for fusion to occur in a self-sustaining way.

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Definitions:

Stimulus Generalization

The process by which a conditioned response is triggered by stimuli that are similar but not identical to the original conditioned stimulus.

Systematic Desensitization

A behavioral therapy technique used to reduce phobic responses and anxiety by gradually exposing the individual to the feared object or situation in a controlled way.

Counterconditioning

A behavior therapy technique that involves pairing a positive stimulus with a fear-evoking stimulus to reduce the fearful response.

Second-order Conditioning

A form of conditioning in which a stimulus is paired with a previously conditioned stimulus, leading to learning without the original unconditioned stimulus.