To find the half-life of uranium-238, we need to add the half-life of uranium-235 (700,000,000 years) to the additional length given (4.463 × 10^11 years).
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Convert 4.463 × 10^11 to decimal form:
- \( 4.463 × 10^{11} = 446,300,000,000 \) years (or 446.3 billion years).
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Now add the two half-lives together: \[ \text{Half-life of } ^{238}\text{U} = 700,000,000 \text{ years} + 446,300,000,000 \text{ years} \] \[ = 447,000,000,000 \text{ years} \]
Therefore, the half-life of uranium-238 is 447,000,000,000 years (or 4.47 × 10^11 years in scientific notation).
So the correct response is: 447,000,000,000.