Why doesn't Rubidium decay to Strontium?

[unscientific]

Both $^{87}_{37}Rb$ and $^{87}_{38}Sr$ are odd-even nuclei, so we can ignore the pairing term $\delta$. I tried to calculate the most stable Z for a given A by finding $\frac{\partial B}{\partial Z} = 0$. That gives the most Z-stable value of $Z_0 = \frac{2\gamma A}{4\gamma + \epsilon A^{\frac{2}{3}}}$ which is $38$ for $A=87$.

If that's the case, then why wouldn't Rb beta decay to Strontium as these are naturally occurring isobars.

 

[jtbell]

why wouldn't Rb beta decay to Strontium

⁸⁷Rb does, in fact, beta-decay with a half-life of about 4.8 x 10¹⁰ years. See e.g. http://www.nndc.bnl.gov/chart/

 

[unscientific]

⁸⁷Rb does, in fact, beta-decay with a half-life of about 4.8 x 10¹⁰ years. See e.g. http://www.nndc.bnl.gov/chart/

Then why is it so stable with such a long half-life?

 

[Vanadium 50]

Then why is it so stable with such a long half-life?

What do you think it's half life should be?

 

[unscientific]

What do you think it's half life should be?

My question is since it is more stable to undergo beta decay, why doesn't it undergo decay quicker? For example uranium 235's half life is 10 times shorter.

 

[Vanadium 50]

For example uranium 235's half life is 10 times shorter.

And Vanadium-50's is a million times longer. What do you think it's half life should be?

 

[unscientific]

And Vanadium-50's is a million times longer. What do you think it's half life should be?

I get your point.