Question

This is an algebra question. I've tried my best to help everyone here so please help me I'm really stuck.It's about scientific notation and needs to be written in it. Thank you so much!!!Question:The half-life of uranium-238 is 4.5×10^9 years. The half-life of uranium-234 is 2.5×10^5. How many times greater is the half-life of uranium-238 than that of uranium-234?

Answer 1

The difference between the half-life of uranium-238 and uranium-234 is:

`4.5\cdot10^9-2.5\cdot10^5`

first we have to write these numbers so that they have the same exponent in 10:

`4.5\cdot10^9=4.5\cdot10^4\cdot10^5=(4.5\cdot10^4)\cdot10^5=45000\cdot10^5`

and now we can take 10⁵ common factor and subtract the decimal numbers:

`(45,000-2.5)\cdot10^5=44,996.5\cdot10^5`

But this is not in scientific notation, we have to move the decimal point to there's just one integer on the left:

`4.49975\cdot10^9`

Half-life of uranium-238 is 4.49975 * 10⁹ times greater than uranium-234