• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Theory of Radioactive decay

Extracts from this document...


Theory of Radioactive decay

1st consider an analogous model.

In the dice analogy of radioactive decay, the number of dice which decayed per throw (∆N) is given by

                ∆N = image01.pngN

                ∆ means a small change

                N is the total number of dice at start

The minus sign indicated that ∆N is ever decreasing and the image02.pngcomes from the probability that advice will show a six when thrown.

2nd – Now consider a real example of radioactive decay. In any such example, if k is the change of decay per second then in a time interval ∆t, a fraction k∆t will decay.

The “k∆t” term here is equivalent to the image10.png

...read more.


image24.png dt

Where Nimage07.png          = number of atoms at time t=0

Where N            = number of atoms at time t=t

image03.pngimage04.png        =image00.png

image03.pngimage05.png =        -kt


image03.pngN = Nimage07.png. eimage08.png

Half life

This is the time taken for N to becomeimage09.png.

i.e. the number of atoms remaining after time t to become equal to half of the original number of atoms present.

...read more.


ity/15668/html/images/image11.png" style="width:41.33px;height:41.33px;margin-left:0px;margin-top:0px;" alt="image11.png" />eimage12.png

Taking log to the base e gives us:

timage13.png = image14.png

The activity of a radioactive material

This is exactly the same thing as its rate of decay. Radioactive sources are marked with “strengths” or activities in curies 1 Curie = 3.7*10image15.png disintegrations per second. OR nowadays in Bequerels 1Bq = 1 disintegration per second.

Since activity = rate of decay.

        A = image17.png

And since

        N = Nimage07.pngeimage08.png

        A = image18.png

image03.pngA = -kNimage07.pngeimage08.png


        N = Nimage07.pngeimage08.png

image03.pngA = -kN

By the use of substitution we come get the following equation.

image20.png A = Aimage07.pngeimage08.png

...read more.

This student written piece of work is one of many that can be found in our GCSE Radioactivity section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Radioactivity essays

  1. To model the sample of radioactivity decay on material, using dice.

    To draw my probability graph I had to follow the theoretical rules to get the curve. The theory is that of atoms are assumed to decay each time they split. On the graph I have drawn y-axis numbered 0 - 100.

  2. Should radioactive smoke alarms be a compulsory purchase?

    cooking so is less likely to be deactivated by owners and could lead to fewer deaths as a result. It does not contain radioactive material which may make it a more appealing option for some households. However, this kind of alarm is less quick to respond to fast flaming fires

  1. Factors affectin cooling rate

    Keep the thermometer away from the edge of the table because the substance released from it is poisonous. 3) Keep the beakers away from the table to avoid any breakages. 4) Pour water in a kettle. 5) Boil the kettle.

  2. What radon is and how it is formed by radioactive decay

    This, in turn, draws in more radon from the ground by concentration-driven diffusion, until an equilibrium radon level is established on each floor. The RadonSeal solution RadonSeal reacts with concrete and seals the capillaries (pores) against radon atoms, as well as the larger water molecules.

  1. Atomic Theory of Matter.

    This is an unstable arrangement, so the tritium nucleus is radioactive. It gives off a negatively charged particle and changes to a stable helium nucleus with two protons and one neutron. Many other isotopes of the various elements are radioactive.

  2. An Investigation To Show The Varying Amounts Of Microbial Decay Caused By The Amounts ...

    I will measure the results with a ruler to measure the size, and also weigh with an electronic weighing scale to find out the weight of the pieces of cabbage. This will enable me to measure to 100ths of a gram so the measurements will be as accurate as possible.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work