Saturday

February 28, 2015

February 28, 2015

Posted by **Star** on Wednesday, November 15, 2006 at 10:57pm.

Assume we start with 100 atoms Rb87 @ t=0 when the fossil just started to form. Then after some time, y will have disintegrated and formed Sr87. Thus 100-y will be the number of Rb87 atoms left.

(Sr87/Rb87)=0.090 from the problem.

y/(100-y)=0.090

Solve for y and 100-y

k = 0.693/t

ln(N

N

N = 100 - y from above.

k = from above

solve for t, the age of the fossil.

**Answer this Question**

**Related Questions**

physics - The rubidium isotope 87Rb is a β emitter that has a half-life of ...

chemistry - the longest lived radioactive isotope yet discovered is the beta-...

Chemistry - Tc-99 is a radioactive isotope that decays by beta emission and is ...

college chemistry - The half-life of 13252Te is 3.26 days. This isotope decays ...

Chemistry - Gallium65, a radioactive isotope of gallium, decays by first order-...

College Geology - assume that a particular radioactive-isotope has a half-life ...

chemistry - Sodium-24, a beta-emitter used in diagnosing circulation problems, ...

Chemistry - What is the famous isotope used in archeological dating? carbon 12 I...

chemistry - What is the half-life of an isotope if it decays to 12.5% of its ...

Chemistry re-post - I took a look at this question to see if I copied it ...