add numbers in scientific notation quick check. the half - life of uranium - 235 is 700,000,000 years. the…

Explanation:

Step1: Write 70000000 in scientific - notation

$70000000 = 7\times10^{7}$

Step2: Add the two numbers

The half - life of uranium - 238 is $4.463\times 10^{11}$ years longer than that of uranium - 235. We add $7\times 10^{7}$ and $4.463\times 10^{11}$. First, rewrite $7\times 10^{7}$ as $0.00007\times 10^{11}$. Then, $(0.00007 + 4.463)\times10^{11}=4.46307\times 10^{11}$. In decimal form, $4.463\times 10^{11}=446300000000$ and $4.46307\times 10^{11}=446307000000$. We made a mistake above. Let's start over. The half - life of uranium - 235 is $70000000 = 7\times10^{7}$ years. The half - life of uranium - 238 is $4.463\times 10^{11}$ years longer. So the half - life of uranium - 238 is $7\times 10^{7}+4.463\times 10^{11}$. We rewrite $7\times 10^{7}$ as $0.00007\times 10^{11}$. $0.00007\times 10^{11}+4.463\times 10^{11}=(0.00007 + 4.463)\times 10^{11}=4.46307\times 10^{11}$. In decimal form: $4.463\times 10^{11}=446300000000$ $4.46307\times 10^{11}=446307000000$ The correct way is to add $70000000$ and $4.463\times 10^{11}$. $4.463\times 10^{11}=446300000000$ $446300000000+70000000 = 447000000000$

Answer:

$447000000000$