Question

Radioactive isotopes can be used to find the age of rocks, fossils, or other artifacts. Carbon-14 has a half-life of 5,730 years. Suppose a sample of charcoal from a primitive fire pit contains one eighth of its original amount of carbon-14. How old is the sample?
A. 716 years
B. 17,190 years
C. 22,920 years
D. 45,840 years
Eh, not exactly math but still appreciate the help :)
Please explain your answer! :D

Answer 1

haven't we been over these problems? do you understand half life?

Answer 2

The way you explained it was awful confusing. Sorry if I seem stupid or whatever.

Answer 3

1/8=(.5)^(t/5730)

Answer 4

n=no*.5*(t/t.5) where t.5 is your halflife and t is your time in years

Answer 5

17190 years

Answer 6

half life is simply the time in which a given sample of radioactive isotope decays into exactly half its original mass.
so suppose you had 1 pound of Uranium 235 isotope. suppose its half life is 10 years.
what that means is, in 10 years the 1 pound will decay into half a pound
.
in another 10 years, it will decay into half the half pound. so that means it will decay into a quarter pound after another 10 years.

Answer 7

http://en.wikipedia.org/wiki/Half-life for more

Answer 8

I still don't get it.
I think that's just my inability to focus though.
Thanks though :)

Answer 9

no worries, the hardest part is solving for t... i used a calculator with a solve function personally

Answer 10

Yea I am just not good at this sort of thing. Writings more my style.
okay I am going to attempt to get this...bear with me if I seem stupid >.<
okay so just explain how you put together the equation if you could :)

Answer 11

step by step.
And we'll see if I get it. LOL

Answer 12

So can you help? :) Step by step like he was gonna? till he forgot :P

Answer 13

Basically it doesnt matter how much there is of the stuff. If you have a piece of uranium that is 100g and a piece that is 200g if they have the same half-life they will both lose HALF of their mass in the same period of time. for example using the two piece above assuming they have a halflife of 10 years.

In ten years time the 100g piece will have degraded into a piece that is approximately 50g.
In the same ten years the 200g piece will have degraded into a piece that is approximately 100g.

Essentially a HALF-LIFE is how long it takes for half of a substance to decay

Answer 14

Wow
I love you.
Haha
Jk but thanks :D
Finally someone who can explain it SIMPLY. :)
Lol

Answer 15

does that need clarifying?

Answer 16

Definitely not xD
Thanks though Paul :)

Answer 17

can i at least get a medal anyway?

Answer 18

Course ^-^

Answer 19

E. Your a science geek. haha :)

Answer 20

that is sOOOOOOOOOOOO not an option xD

Answer 21

i just gave my wifey like a thousand medals lol and now I shall forever again. Answer yo email <3