Radioactivity.

[ed84c]

Right imagine a Piece of Radioactive material. We have been steadily decaying for many years. Finally there is just 1 stable isotope ready to go under alpha decay. The atom has a half life of one day. But wait we cant have 1/2 a decayed atom at the end of the day, so is it totally a random chance whether the atom will decay in one day? (yes i know QM says its random anyway).

 

Now im pretty sure the GCSE course is about to make us draw graphs that curve off and it will probably tell us it never hits the x axis, but if the answer is yes to the above question, then it must do. Or will we be tought its just slows and does (randomly) touch the x axis sometime in the future?

[5614]

if you imagine you have uranium 238 that decays into uranium 234, so its not like the whole atom decays at once, one second you have U-238 and the next you dont, its just one second you have U-238 and the next you have a different element.... in the end the atom will become stable and then it will no longer decay.

[ed84c]

what if u have only one atom?

[swansont]

The statistics used to descibe decay assume large samples. Small samples will deviate from large-sample behavior. You can deduce the probability of decay, but not predict the actual behavior. Similarly, you may know half of the atoms in a sample will decay in a half-life, but you can't tell when any one nucleus will decay.

[5614]

so you could have one radioactive or unstable nucleus (the element has a half life of 2 day or 24 hours) but yet you have no clue when it will really decay or emit radiation?

[[Tycho?]]

A stable isotope will not decay. Otherwise it wouldn't be stable.

[ed84c]

yes; aparantly 'God Does play dice'

[JaKiri]

so you could have one radioactive or unstable nucleus (the element has a half life of 2 day or 24 hours) but yet you have no clue when it will really decay or emit radiation?

 

Indeed. Like when rolling a die, you may never get to 6.

[rakave]

er...........................

[rakave]

It's not like if an element is radioactive it's gonna constantly emit it's alpha,beta or gamma radiation. Eventually it has to form a stable element.

[J.C.MacSwell]

so you could have one radioactive or unstable nucleus (the element has a half life of 2 day or 24 hours) but yet you have no clue when it will really decay or emit radiation?

 

You have a "clue". If it has a one day half life it has a 50% chance of decaying in the "next" 24 hours.