i understand vaguely what it means, sort of.. but i don't get how to work it out.

also... if anyone can explain 'red shift' to me too.. that'd be great :)

and the half life of the balls is 50 years

after 50 years you'll have 50 balls

after 100 years you'll have 25 balls

and so on

just google it

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Ie. Carbon -13

Half life 1000years

So in a thousand years you'll have half the amount of carbon 13 as you did when you started.

in 2000 1/4, in 3000 1/8

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How I wish, how I wish you were here.
We're just two lost souls swimming in a fish bowl.

yeah.. that's the part i understand, all the examples i have are like that.

but when it comes to an exam.. past paper or something.. the question is like this:

"A sample of charcoal from the stone age campfire contains 12 billion carbon-14 atons.
approximately how many carbon-14 atoms would the sample have contained 6000 years ago?
a) 6 billion
b) 12 billion
3) 24 billion
4) 48 billion"

and it's those sotrs of questions i don't know how to work out. :S

I'd assume it's 3 or 6 thousand years.


-------
How I wish, how I wish you were here.
We're just two lost souls swimming in a fish bowl.

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thankyou for replying :)

yeah.. that's the part i understand, all the examples i have are like that.

but when it comes to an exam.. past paper or something.. the question is like this:

"A sample of charcoal from the stone age campfire contains 12 billion carbon-14 atons.
approximately how many carbon-14 atoms would the sample have contained 6000 years ago?
a) 6 billion
b) 12 billion
3) 24 billion
4) 48 billion"

 
and it's those sotrs of questions i don't know how to work out. :S

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wiki tells me the half life is 5,730

this is GCSE so im going to assume you take the half life to be 6000

you know that every 6000 years the samply halves, so 6000 years ago it would be double what it is now

or 24million

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Peer Answers. Peer Support. Period.
http://www.teenhut.net/

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Quote: from rosiewantspancakes at 6:16 am on Nov. 19, 2008

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thankyou for replying :)  

 yeah.. that's the part i understand, all the examples i have are like that.  

 but when it comes to an exam.. past paper or something.. the question is like this:  

 "A sample of charcoal from the stone age campfire contains 12 billion carbon-14 atons.  
 approximately how many carbon-14 atoms would the sample have contained 6000 years ago?  
 a) 6 billion  
 b) 12 billion  
 3) 24 billion  
 4) 48 billion"  

 
 and it's those sotrs of questions i don't know how to work out. :S

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wiki tells me the half life is 5,730

this is GCSE so im going to assume you take the half life to be 6000  

you know that every 6000 years the samply halves, so 6000 years ago it would be double what it is now

or 24million

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eh i mean billion

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Peer Answers. Peer Support. Period.
http://www.teenhut.net/

"carbon-14 decays by emitting beta particles and it's half like is 5730 years."

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Quote: from Medevac at 6:19 am on Nov. 19, 2008

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Quote: from rosiewantspancakes at 6:16 am on Nov. 19, 2008

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thankyou for replying :)

  yeah.. that's the part i understand, all the examples i have are like that.

  but when it comes to an exam.. past paper or something.. the question is like this:

  "A sample of charcoal from the stone age campfire contains 12 billion carbon-14 atons.
  approximately how many carbon-14 atoms would the sample have contained 6000 years ago?
  a) 6 billion
  b) 12 billion
  3) 24 billion
  4) 48 billion"

   
  and it's those sotrs of questions i don't know how to work out. :S

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 wiki tells me the half life is 5,730  

 this is GCSE so im going to assume you take the half life to be 6000

 you know that every 6000 years the samply halves, so 6000 years ago it would be double what it is now  

 or 24million

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eh i mean billion

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^^^^^ this 24 bil if they give you the Half life as 6k.

They've changed GCSE since I did it so you may need to know certain half lives.

-------
How I wish, how I wish you were here.
We're just two lost souls swimming in a fish bowl.

because I make it 24.8 x10^9

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How I wish, how I wish you were here.
We're just two lost souls swimming in a fish bowl.

"A sample of charcoal from the stone age campfire contains 12 billion carbon-14 atons.
approximately how many carbon-14 atoms would the sample have contained 6000 years ago?
a) 6 billion
b) 12 billion
3) 24 billion
4) 48 billion"

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yeah, i am. it's multichoice paper too, so at least that's a consilation!

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I say B. I always pick a letter at the start of any multi choice exam to use as my guess.

-------
How I wish, how I wish you were here.
We're just two lost souls swimming in a fish bowl.