Which Proportion of a Radioactive Isotope Is Expected to Remain

question 10

Multiple Choice

Which proportion of a radioactive isotope is expected to remain in an unaltered (unreacted) state after the passage of three half-lives?

• A)one-third
• B)three-halves
• C)one-eighth
• D)one-sixth

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Definitions:

Hypothalamus

A region of the brain below the thalamus, important for hormone production and regulation of body temperature, hunger, thirst, and emotional behavior.

Pituitary Gland

A small, pea-shaped gland located at the base of the brain, crucial for regulating vital body functions and general well-being through the secretion of hormones.

Disinhibition Theory

A theory suggesting that reduced inhibition of specific neurons or brain regions can lead to an increase in functional activity, often discussed in the context of behavioral psychology.

Behavioral Myopia

“Nearsighted” behavior displayed under the influence of alcohol, wherein local and immediate cues become prominent; remote cues and consequences are ignored.