A Rock Contains 0 $\rarr$ ²⁰⁶Pb Is 4

question 68

Multiple Choice

A rock contains 0.37 mg of Pb-206 and 0.95 mg of U-238. Approximately how many U-238 atoms were in the rock when it was formed billions of years ago (The half life for ²³⁸U $\rarr$ ²⁰⁶Pb is 4.5 * 10⁹ yr.)

• A) 1.32 atoms
• B) 5.8 * 10^-6 atoms
• C) 2.4 * 10¹⁸ atoms
• D) 3.5 * 10¹⁸ atoms
• E) 3.5 * 10²¹ atoms

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Definitions:

Powerlessness

A state of feeling unable to control, influence, or effectively act in a situation, often leading to frustration and vulnerability.

Acute Mania

A phase of bipolar disorder characterized by an elevated mood, overactivity, rapid speech, and impulsive behavior.

Pressured Speech

Rapid, frenzied, or uninterrupted speech that is a characteristic of certain psychological disorders, such as bipolar disorder during manic phases.

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Detailed and extensive written remarks or observations.