.
The number of half-lives of the carbon-14 in 13000 years is this fraction/(ratio)
= 2.253.
So, there are 2.253 half-life periods in 13000 years.
The fraction of the original carbon-14 amount remaining after 13000 years is
f = = = 0.210 (rounded).
Or, expressed as a percentage, 21%.
Solved.
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To see many other similar solved problems, see the lesson
- Using logarithms to solve real world problems
- Radioactive decay problems
- Carbon dating problems
in this site.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Logarithms".
Save the link to this online textbook together with its description
Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson
to your archive and use it when it is needed.