Radioactivity (with or without the resources) 

Elon Musk: Odds are we’re living in a simulation”

The terms radiation’ and radioactivity’ are often interchangeable in the public mind. Because of its invisibility, radiation is commonly feared.

True or false

1.Radioactive substances make everything near to them radioactive.

2.Once something has become radioactive, there is nothing you can do about it.

3.Some radioactive substances are more dangerous than others.

4.Radioactive means giving off radio-waves.

5.Saying that a radioactive substance has a half life of three days means any produced now will all be gone in six days

Story: Chernobyl

In April 1986, a serious accident occurred at the nuclear power station at Chernobyl in Russia. A week later, radiation detectors (Geiger counters) in Britain recorded higher  than usual levels of radiation. Britain is more than 1000 miles from Chernobyl!                     

Explain what reached the Geiger counters in Britain to make them record extra counts.

Misconception Alert:

•Many students confuse radiation’ and radioactive material’.

•After the Chernobyl accident, many newspaper articles referred to a “cloud of radiation” and drinking water contaminated with “radiation”.

Misconception Alert:

Many students appear to interpret the idea that radiation is absorbed” differently from the scientific interpretation. They believe that objects that have been irradiated will themselves become radioactive — that they can re-emit the radiation some time later.

The underlying idea here is that they seem to think that radiation is somehow conserved”. 


•An inability to distinguish between the ideas of irradiation and contamination

•An inability to interpret the ideas of activity and dose

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What is radioactive”

The Radiation Protection Division of the Health Protection Agency defines a radioactive substance as having a specific activity ³ 400 Bq/kg.

Some Stories:

•1841- Eugene Peligot discovers uranium

•1895 — William Roentgen discovers X-rays

•1896 — Henri Becquerel discovers that rocks that contain uranium emit radiation

•1988/9 — Marie Curie discovers radium, polonium and thorium

•1903 — Becquerel, and the Curies get Nobel Prize

The notebook that needs to be stored in a lead box

Story: Why green?

The miracle cure’

10/10 on the Canard scale!

Image result for radon mine health cure

GCSE stuff:

The Strong Force.


File:Spark counter.webm - Wikimedia Commons

Mini Instruments Type 5.10 and 5.40 Geiger Counters

Ionisation Chambers


Beta Decay

Magnetic steering

Related image


Neutrino - Wikipedia

King’s physicists herald Big Bang breakthrough in particle physics


All particles of normal matter, such as protons, neutrons and electrons have a corresponding particle that:

1.has the same mass as the normal particle

2.has opposite charge (if the normal particle   is charged)

3.will undergo annihilation with the normal   particle if they meet

Electron Capture

Without resources:

Radioactivity all around!


decay table

People are radioactive - Typically 7000 Bq. So it’s dangerous to sleep with somebody”! However, most of the resulting radiation is absorbed within the owners’ body.

Brazil nuts (especially the ones grown in Brazil) grow on trees with deep and very extensive roots, the soil where a lot of the trees grow in brazil is high in radium, which then makes its way to the nuts. As a result, the radium levels of Brazil nuts can be 1000 times what you’d see in other foods. Brazil nuts not grown in Brazil are often not radioactive!

Sort-of sources:

Gas Mantles

Thoriated welding rod

Uranium Glass

Image result for uranium glass


Health Physics Posters | Museum of Radiation and Radioactivity

The sources

Image result for school radioactive sources

School radioactive sources

Uses of radioactivity


gamma knife

tiger in cat scan


Smoke detector 

graph of c14decay

Stability and decay:

Decay and half life

Beware of simulations!

Pearson - The Biology Place

Beer, cake, water from a bottle.



Dice rolling - 

Why the dice rolling model is wrong: (

# some library objects we need

from numpy.random import binomial, seed

from numpy import zeros, arange

from matplotlib import pyplot as plt

# initial population

P0 = 80

# number of rolls per experiment

n_rolls = 50

# number of experiments

n_exp = 1

# probability that any given die will decay” on a given roll

p = 1/6

# location to track average dice remaining for each roll number

pop_avg = zeros(n_rolls+1)

# seed” the random number generator

# (This makes the results look different

# each time the code is run.)


# loop over experiments

for n in range(n_exp):

  # reset the dice population

  P = P0

  # roll the dice

  for k in range(1,n_rolls+1):

    # figure out how many dice decay this time

    r = binomial(P,p)

    # remove the dice

    P -= r

    # update the average

    pop_avg[k] += P

# final division to compute the averages

pop_avg /= n_exp

# we always started with P0

pop_avg[0] = P0

# compute the model predictions

model = (1.0-p)**arange(n_rolls+1.0)*P0

pl1 = list_plot(pop_avg,plotjoined=True,marker=‘+’,legend_label=‘Model results’,axes_labels=[‘roll #‘, # dice’])

pl2 = list_plot(model,plotjoined=True,linestyle=‘–’,color=‘red’,marker=‘x’,legend_label=‘Theoretical curve’)



Saxa Vord radar base on Unst in Shetland was believed to be a probable nuclear target in the 1970s

Nuclear Power

Nuclear Fission vs Fusion - Nuclear Power


Discovery of nuclear fission - Wikipedia


Is Fusion Power Within Our Grasp?

DOE Explains…Nuclear Fusion Reactions | Department of Energy

Fun things to do:

Stop motion with lego/plasticine

Mr Tompkins in paperback (literacy)

Cloud chambers

Chain reaction

Chain Reaction | Pepsi Max | #LiveForNow - YouTube

Stop motion

Rutherford experiment


Dodgeball analogy

Teaching Order

Group 1. A phenomenological orientation.

Lesson 1. Source -> radiation -> detector model. Phenomena including light, infra-red and radioactivity can all be interpreted using this model.

Group 2. Qualitative macroscopic treatment.

Lesson 2. What happens when radiation is absorbed? Demonstrations using light show that the radiation can be absorbed and is no longer there. The absorber does not consequently become a light source.

Lesson 3. Three types of radiation. Experiments to show that there are three types of radiation from radioactive sources. These can be found in the Teachers TV programme.

Lesson 4. Radioactivity all around us. Introduces the idea that there are weak sources of radioactivity all around us - background radiation.

Lesson 5. Open and closed sources. The UYSEG scheme uses a simulation of the Chernobyl accident to distinguish between open and closed sources and the ideas of contamination and irradiation.

Lesson 6. Putting radioactive sources to use. For example as tracers and in medicine.

Group 3. A quantitative macroscopic treatment.

Lesson 7. Comparing sources. Activity and half life. The demonstrations and activities from the programme could be used here.

Lesson 8. Radiation dose. How much do we get? The background radiation worksheet could be used here.

Group 4. A treatment at the atomic level.

Lesson 9. Atoms, nuclei and transmutations. Only now are students introduced to an explanation at an atomic level. They consider the evidence for the explanations. The animations from the programme would be useful in this lesson.

Lesson 10. Randomness and chance. Simulations using dice and coins. The activities from the programme could be used here.