Heavy Nuclei Are Unstable Because

question 20

Multiple Choice

Heavy nuclei are unstable because

• A) each nucleon is a separate particle that is not acted on by the nuclear force.
• B) there are not enough protons present relative to the number of neutrons for the electrical force to be strong enough.
• C) the nuclear force dominates the Coulomb repulsive force at distances less than 2 fm, but falls off rapidly at greater distances.
• D) nuclei are stable only when the number of neutrons equals the number of protons.
• E) nuclei are stable only when the number of protons exceeds the number of neutrons.

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Definitions:

Barbiturates

A class of drugs derived from barbituric acid, used as sedatives and hypnotics, which can depress the central nervous system.

Caffeine

A stimulant compound found in coffee, tea, chocolate, and many soft drinks, which acts on the central nervous system to reduce tiredness and improve concentration and focus.

Alertness

The state of being watchful and prompt to meet danger or emergency, or to discover and avoid errors.

Neurochemical Properties

Characteristics and behaviors of the chemicals in the nervous system that influence brain function and behavior.