The Lifetime of Uranium 238 Is 6

question 14

Multiple Choice

The lifetime of uranium 238 is 6.0 × 10⁹ y, and that of uranium 235 is 1.0 × 10⁹ y. The present abundance of uranium 238 is 140 times the abundance of uranium 235. What was the ratio of abundances 1 billion years ago?

• A)140:1
• B)6:1
• C)61:1
• D)161:1
• E)322:1

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Definitions:

Vygotsky's Theory

A theory of cognitive development that emphasizes the role of social interaction and culture in the development of higher mental functions.

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Time when a particular development must occur. If it does not, as when something toxic prevents that growth, then it cannot develop later.

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A developmental period from birth to approximately eight years of age, characterized by rapid physical, cognitive, and emotional growth.

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The process through which individuals acquire the ability to comprehend and communicate in languages other than their native language.