decay constant

asked by @jankj3 • over 1 year ago • Chemistry • 5 pts

if 1.0010^-12 mol of 135 Cs emits 1.3910^5 b- particles in 1.00 yr, what is the decay constant?

How is this even possible to solve? There are more b- partices emitted than actualy C atoms.

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3 answers

Hey there. So recall that all radioactive processes occur as 1st order. So, you use the first order equation. Here, your decay constant is the same as the K constant, meaning you are solving for K.

First thing is first, make sure you have all of the other variables' values in order to accurately solve for K.

You are given the initial concentration but in moles, and you want beta particles (since the loss of concentration is given in terms of beta particles). Convert the moles to beta particles.

Now you must solve for the final concentration. Use the initial concentration and take away the beta particles that got emitted or lost.

Now you have everything to solve for K. Remember that T here is the time, which was given as 1 year. The rest is simply plugging in. Hope this helps! Let us know if you have any other questions/concerns.

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answered by @sabrina • over 1 year ago

Thanks! I forgot to convert moles to particles.

answered by @jankj3 • over 1 year ago

No problem!

answered by @sabrina • over 1 year ago