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1

It depends what you mean by controlled. Without going into the details of each decay process you mention ($\alpha, \beta, \gamma$), the decay of an unstable nucleus is inherently random. At a quantum mechanical level, we can think of the system changing from one eigen-state to another and that is fundamentally unpredictable (this is the bit that Einstein ...

2

There is no reason why you can't measure the rate frequently. However, in order to estimate the half life, you need to see a change in the rate of decay. How long you need to measure for, and how far apart you need to change your measurements, depends on the number of decays per second that you observe as well as the required accuracy. For example, if you ...

0

you should resolve the differential equation of N. If you do that you'll get that $$A = A_0 e^{\lambda (t-t_0)},$$ where $A_0$ is the activity at time $t_0$. From there you can obtain the value of $\lambda$ from two measurements of the activity whatever the time interval.

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Firstly, the activity formula is in fact: $$-\frac{dN}{dt}=A=λN,$$ because $\frac{dN}{dt}<0$. [...] is there any particular reason why our time interval for measuring the number of remaining Radionuclides should be close to the half-life of the substance? No and that's not how it's done in practice. $\lambda$ and the half-life are determined by ...

2

Ionizing radiation is radiation that is strong enough so that, when it hits an atom or molecule, will knock off electrons. This happens even if the target object doesn't have freely mobile electrons, which leaves free radicals and broken bonds, both of which are harmful to complex biological processes. There's no selection based on electron binding energy; ...

2

Use the Evaluated Nuclear Structure Data File; search "by decay" and put the nuclide you'd like to start with in "parent." This will also tell you half-lives and Q-values. A few nuclides have multiple decay modes; for instance radon-221 usually beta-decays to francium-221, but alpha-decays to polonium-217 about 22% of the time. You may find other "forks ...

0

Theoretically speaking, of course, if your true linear speed with respect to the true center of the universe was zero, you would be experiencing true time. Even on Earth, who's movement is what we base our time (e.i. seconds, days, years, etc) off of, we theoretically would be experiencing time dilation based on Lorentz, assuming that at a true zero ...

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Originally radioactive elements come from nature where they were very diluted and that's why they were secure. When these naturally radioactive materials like Uranium are used in processes like civilian nuclear energy production the resulting waste becomes many, many times more radioactive than the raw materials one started off with. Even after the ...

3

Probably too expensive and disruptive to try to deal with nuclear waste that way. You're talking about processing through an enormous amount of earth and/or seawater. Note that nuclear waste includes not just material that was initially radioactive when it came out of the ground (e.g., uranium ore), but a lot more material as well. If a nuclear plant worker ...

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One on the problem is re-concentration, by the help of water circulation in the soil (possibly up to water sources) or by the help of small animals (then to food chain up to us). The stability of geological layers is not so easy to predict. Beside, the radio-activity of wastes can be a lot higher, and spreaded through a huge variety of chimical species, ...

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