Question

the half - life of uranium - 235 is 700,000,000 years. the half - life of uranium - 238 is 4.463×10^{11} years longer. what is the half - life of uranium - 238? the answer should be in decimal form. (1 point)
○ 516,300,000,000
○ 447,000,000,000
○ 4.4637×10^{11}
○ 11,463,000,000

Explanation:

Step1: Write uranium - 235 half - life in scientific notation

$700000000 = 7\times10^{8}$

Step2: Add the difference to uranium - 235 half - life

$7\times 10^{8}+4.463\times 10^{11}$
First, rewrite $7\times 10^{8}$ as $0.007\times 10^{11}$
Then $0.007\times 10^{11}+4.463\times 10^{11}=(0.007 + 4.463)\times10^{11}=4.47\times 10^{11}$
Convert to decimal form: $4.47\times 10^{11}=447000000000$

Answer:

$447000000000$ (None of the given options are correct based on the above calculation. If we assume there is a mis - typing in the problem setup and we just do the addition in a non - scientific - notation way: $700000000+446300000000 = 447000000000$)