Welcome Guest Search | Active Topics |

Tag as favorite
Question 15 from Page 60 in In Class Exam
Mariam_6809
#1 Posted : Tuesday, June 08, 2021 12:35:11 AM
Rank: Newbie

Groups: Registered
Joined: 5/27/2021
Posts: 5

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Hi! I am a little confused about how I should go about doing 15. I know we took it up in class, but my wifi glitched thus I missed it.
INSTR_Katrina_128
#2 Posted : Tuesday, June 08, 2021 6:39:17 PM
Rank: Advanced Member

Groups: Registered
Joined: 5/18/2021
Posts: 60

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Was this perhaps Review Question 15 on page 60 of the Classroom Companion?

In the passage, we are told that the half life of carbon-14 is 5730 years. Let's round that to 5700 years for easier math.

Let's assume today is today! Wow.

If we start with 100% carbon-14, then in 5700 years, we will have 50% carbon-14. In another 5700 years (or a total of 11400 years), we will have 25% carbon-14. In another 5700 years (or a total of 17100 years), we will have 12.5% carbon-14.

In summary:
100% remaining - 0 years
50% remaining - 5700 years
25% remaining - 11400 years
12.5% remaining - 17100 years

We are told that a fossil contains 20% carbon-14.

It must have a lifespan between 11400 and 17100 years.

The answer is EITHER B or C. A and D are eliminated.

Since 20% is approximately halfway between 25% and 12.5%, then the lifespan should be approximately halfway between 11400 and 17100 years. So, C is the best answer!
Users browsing this topic
Guest
Tag as favorite
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Clean Slate theme by Jaben Cargman (Tiny Gecko)
Powered by YAF | YAF © 2003-2009, Yet Another Forum.NET
This page was generated in 0.084 seconds.