× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
r
4
Home Q & A Board Science-Related Homework Help Physics
New Topic  
stellarelli stellarelli
wrote...
Go to Answer
Posts: 500
Rep: 0 0
6 years ago
In a record from 12,370 carbon-14 years before the present to the present time, Ref. 59 finds that there was a decreasing lead-206/lead-207 ratio in deposited lead starting 3000 carbon-14 years ago. This is an indicator of lead mining.
 
  a. If the pre-anthropogenic deposition rate is 0.01 milligram per square meter per year, andthe highest rate found was 15.7 milligrams per square meter per year in 1979, determine therelative effect of humans in 1979
 b. How much more lead is being used in 1979 relative to 100, if the deposition in the year
  100 were 0.12 milligrams per square meter per year?
Read 53 times
1 Reply
Replies
Answer verified by a subject expert
omar.quesadamedomar.quesadamed
wrote...
#1
Posts: 345
Rep: 1 0
6 years ago
Sign in or Sign up in seconds to unlock everything for free
1

Related Topics

stellarelli Author
wrote...

6 years ago
This site is awesome
vanna2014
wrote...

Yesterday
Correct Slight Smile TY
gage
wrote...

2 hours ago
Good timing, thanks!
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1215 People Browsing
 124 Signed Up Today
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Related Images
  
 891
  
 318
  
 40
Your Opinion
Previous poll results: Which country would you like to visit for its food?