Station 10 – The Nucleus
1. What are the two subatomic particles in the Nucleus and what are their respective char
2. Define proton number and nucleon number.
3. For the following, determine the proton number and mass number and thus the element as
Nuclide
Notation
Proton Number
Nucleon
Number
Element?
23
11𝑋
37
17𝑋
4. Define the term isotope and explain why some of them are radioactive.
5. For each of the following isotopes, write the nuclide notation.
a. Polonium-210
b. Strontium-90
c. Uranium-235
6. Compare and contrast the processes of nuclear fission and nuclear fusion.
Station 11 - Radioactivity
1. Define ionizing nuclear radiation.
2. Define background radiation.
3. Identify 4 significant sources of background radiation.
4. What equipment can be used to measure ionizing nuclear radiation?
5. How does the equipment measure it?
6. After 60 seconds a radiation counter detects about 20 radioactive emissions on average
Station 12 – Nuclear Emissions
1.What nuclide is an alpha particle equivalent to?
2.What is a beta particle also known as?
3.Rank the ionizing effects of alpha, beta and gamma
emissions.
4.Rank the relative penetrating abilities of alpha,
beta and gamma emissions.
5.Which emissions would be blocked by:
a.A sheet of paper?
b.A sheet of aluminium?
Station 13 – Radioactive Decay &
Half-life
1. Which types of decay alters the nucleus of an atom to a
different element?
2. Write the equation for the alpha decay of uranium-238.
3. Write the equation for the beta decay of thorium-234.
4. Why does the nucleon number not change during beta decay?
Where does the beta-particle come from?
5. Determine the half-life of the following substance. Using
the graph on the right.
6. Cesium-137 has a half-life of 30 years. If we start with
100 kg of cesium-137. How much would be have after:
a. 30 years?
b. 120 years?
7. Krypton-81 has a half-life of 13 seconds. If we start with
50 g of Krypton-81, how many half-lives would it take to
have less than 2 g of Krypton-81 remaining? What is the
minimum number of seconds that this would take?
Station 14 – Nuclear
Applications
&
Safety
1.State five different applications of radioactivity or
radioactive isotopes.
2.What are the three effects of ionizing nuclear radiation on
living things?
3.To minimize the effect of radioactive material emissions,
how should they be moved, used or stored in a safe way in
terms of:
1.Exposure time
2.Distance of exposure
3.Shielding
Station 10 – The Nucleus
1. What are the two subatomic particles in the Nucleus and what are their respective char
Neutrons which are neutral, protons which have a +1 charge
2. Define proton number and nucleon number.
Proton number is the number of protons in a nucleus, nucleon number is total number of
3. For the following, determine the proton number and mass number and thus the element as
Nuclide
Notation
23
11𝑋
37
17𝑋
Proton Number
Nucleon
Number
Element?
11
23
Sodium
17
37
Chlorine
4. Define the term isotope and explain why some of them are radioactive.
Isotopes are atoms with the same number of protons but a different number of neutrons.
The different number of neutrons can cause the nucleus to be unstable and thus radioac
5. For each of the following isotopes, write the nuclide notation.
210
a. Polonium-210
84𝑃𝑜
90
b. Strontium-90
38𝑆𝑟
c. Uranium-235 235
92𝑈
6. Compare and contrast the processes of nuclear fission and nuclear fusion.
Nuclear fission and fusion both produce energy
Fission is the splitting of a nucleus while fusion is the combination of multiple nucl
Station 11 - Radioactivity
1. Define ionizing nuclear radiation.
Ionizing nuclear radiation is radiation that can knock electrons off atoms to cause
them to ionize (become ions)
2. Define background radiation.
Background radiation is ionizing radiation that is always present in the
environment.
3. Identify 4 significant sources of background radiation.
Radon gas, rocks and buildings (containing radioactive minerals), food & drink
(containing radioactive isotopes such as potassium-40), cosmic rays
4. What equipment can be used to measure ionizing nuclear radiation?
Geiger counter
5. How does the equipment measure it?
Gas inside the counter is ionized which conducts electricity. The counter detects
the number of such events over a period of time to determine the count rate.
6. After 60 seconds a radiation counter detects about 20 radioactive emissions on
average. What is the count rate?
Station 12 – Nuclear Emissions
1.What nuclide is an alpha particle equivalent to?
Equivalent to a helium-4 nuclide.
2.What is a beta particle also known as?
Electron
3.Rank the ionizing effects of alpha, beta and gamma emissions.
Alpha > beta > gamma
4.Rank the relative penetrating abilities of alpha, beta and
gamma emissions.
Gamma > beta > alpha
5.Which emissions would be blocked by:
a.A sheet of paper? Alpha
b.A sheet of aluminium? Alpha & Beta
c.A layer of lead? Alpha, Beta & Gamma
Station 13 – Radioactive Decay &
Half-life
1. Which types of decay alters the nucleus of an atom to a
different element?
Alpha and beta decay
2. Write the equation for the alpha decay of uranium-238.
238𝑈 → 234𝑇ℎ + 4𝛼 or 238𝑈 → 234𝑇ℎ + 4𝐻𝑒
92
92
2
90
2
90
3. Write the equation for the beta decay of thorium-234.
234
234
234
234
0
0
90𝑇ℎ → 91𝑇ℎ + −1𝑒 or
90𝑇ℎ → 91𝑇ℎ + −1𝛽
4. Why does the nucleon number not change during beta decay?
Where does the beta-particle come from?
The beta-particle comes from a neutron that decays into a
proton and electron (beta-particle). Therefore, the nucleon
number does not change as a neutron has become a proton,
which only changes proton number.
5. Determine the half-life of the following substance. Using
the graph on the right.
1.5 hours (to go from 80 to 40, which is half)
6. Cesium-137 has a half-life of 30 years. If we start with
100 kg of cesium-137. How much would be have after:
a. 30 years? 50 kg
1
b. 120 years? (120/30)=4 half lives, ( )4 × 100 = 6.25 𝑘𝑔
2
7. Krypton-81 has a half-life of 13 seconds. If we start with
50 g of Krypton-81, how many half-lives would it take to
have less than 2 g of Krypton-81 remaining? What is the
Station 14 – Nuclear
Applications
&
Safety
1.State five different applications of radioactivity or
radioactive isotopes.
•
•
•
•
•
Household fire alarms
Killing bacteria in food
Sterilisation of equipment
Measuring and controlling of material thickness
Diagnosis and treatment of cancer
2. What are the three effects of ionizing nuclear radiation on
living things?
Causes mutations, cell death, cancer
3. To minimize the effect of radioactive material emissions,
how should they be moved, used or stored in a safe way in
terms of:
1.Exposure time Minimize exposure time
2.Distance of exposure Increase distance from source
3.Shielding Use appropriate shielding based on emissions