Finding the activity of a carbon 14 sample

[Bolter]

Homework Statement

See full question below

Relevant Equations

A = Lambda*N

Hi there

So I have had a go at this question but I'm not confident that I have done the last 2 parts of this question right?

Can anyone please see if this is what you do to get the values?

Any help would be appreciated! Thanks

 

[haruspex]

Think again about how you calculate the number of C14 atoms in the 1g.

 

[Bolter]

Think again about how you calculate the number of C14 atoms in the 1g.

Is this what I should get instead?

I don't know why I was using 14 as the molar mass of carbon-12

 

[etotheipi]

I don't know why I was using 14 as the molar mass of carbon-12

That appears to be a good enough approximation considering the huge excess of carbon-12, good enough for the precision of my calculator, anyway!

If the proportions were less extreme, you'd need to perhaps consider using a weighted mean or else an algebraic expression of some sort for the relative masses.

 

[Bolter]

That appears to be a good enough approximation considering the huge excess of carbon-12, good enough for the precision of my calculator, anyway!

If the proportions were less extreme, you'd need to perhaps consider using a weighted mean or else an algebraic expression of some sort for the relative masses.

Thanks I understand, and notably this means my answer will be affected for part e) as part e) relies on part d)

I changed it now and found the time that the activity will reduce to 3 disintegrations per min assuming 11.835... is the initial activity in disintegrations per min