Course: Combined and Separate | Find each scene on YouTube, watch it, then answer the questions. Write your answers on paper first, then tap Show answer.
Remember: Half-life is the time for the number of unstable nuclei (or the count rate) to halve. · Alpha is stopped by paper, beta by a few mm of aluminium, gamma is reduced by thick lead or concrete. · Radius of an atom ≈ 1 × 10⁻¹⁰ m.
1. The Simpsons – the glowing rod (opening titles)
🎬 The scene: In the opening titles, Homer handles a glowing rod at the power plant with tongs – then finds it down his shirt in the car and throws it out of the window.
Q1 (F) Homer handles the radioactive rod with tongs. How do tongs reduce his risk?
Show answer
They keep the source further away from his body, so less radiation reaches him.
Q2 (F/H) The rod falls down his shirt. Is this irradiation or contamination? What would make it the other one?
Show answer
Irradiation – he is exposed to radiation from a source outside his body. It would be contamination if radioactive atoms got on his skin or inside him, e.g. by breathing in dust from the rod.
Q3 (H) Uranium-235 has an atomic number of 92. How many protons, neutrons and electrons does an atom of it have?
Show answer
92 protons, 143 neutrons (235 − 92) and 92 electrons.
2. The Simpsons – a radioactive tracer
🎬 The scene: In “Homer’s Triple Bypass”, Dr Hibbert shows a scan of radioactive dye flowing through Homer’s blood vessels.
Q1 (F) A medical tracer is injected into the blood. Why does it need to give out gamma radiation, not alpha?
Show answer
Gamma can pass out of the body to be detected by a camera outside. Alpha would be absorbed inside the body, where it is very ionising and harmful.
Q2 (F/H) Why should a tracer have a short half-life (a few hours)?
Show answer
Long enough to do the scan, but short enough that it doesn’t stay radioactive in the body for long, so the patient’s dose is low.
Q3 (H) A tracer has a half-life of 6 hours. What fraction is left after 24 hours?
Show answer
24 ÷ 6 = 4 half-lives. ½ × ½ × ½ × ½ = 1/16
3. Spider-Man 2 – Dr Octavius’s fusion experiment
🎬 The scene: Dr Otto Octavius demonstrates his fusion reactor – “the power of the sun in the palm of my hand” – before it goes wrong.
Q1 (F) What is nuclear fusion?
Show answer
Two light nuclei join to form a heavier nucleus, releasing energy.
Q2 (F/H) He calls it “the power of the sun”. Where does fusion happen naturally?
Show answer
In stars, including the Sun, where hydrogen nuclei fuse to make helium.
Q3 (H) Explain why fusion is so hard to achieve on Earth.
Show answer
Nuclei are positively charged, so they repel each other. Extremely high temperatures and pressures are needed to get them close enough to fuse, and these are very hard to create and contain.
4. Radioactive – the story of Marie Curie
🎬 The trailer: Rosamund Pike plays Marie Curie, who discovered radium and polonium – without knowing how dangerous they were.
Q1 (F) What is radioactive decay?
Show answer
An unstable nucleus gives out radiation to become more stable. It is a random process.
Q2 (F/H) Marie Curie carried radioactive samples in her pockets and later became very ill. Explain why ionising radiation is dangerous.
Show answer
It can damage cells and DNA, killing cells or causing mutations that can lead to cancer. Nobody knew the dangers then – that’s why her notebooks are still kept in lead-lined boxes today.
Q3 (H) Radium-226 has a half-life of 1600 years. A sample has an activity of 32 000 Bq. What will its activity be after 4800 years?
Show answer
4800 ÷ 1600 = 3 half-lives. 32 000 → 16 000 → 8000 → 4000 Bq
5. Jurassic Park – Mr DNA and the mosquito in amber
🎬 The scene: The cartoon Mr DNA explains how dinosaur DNA was taken from mosquitoes trapped in amber millions of years ago.
Q1 (F) Carbon-14 is used to date old things that were once alive. Its half-life is 5730 years. What does this mean?
Show answer
Every 5730 years, half of the carbon-14 nuclei in a sample decay.
Q2 (F/H) What fraction of the original carbon-14 is left after 11 460 years?
Show answer
11 460 ÷ 5730 = 2 half-lives. ½ × ½ = ¼
Q3 (H) Real or fake? The mosquito is about 65 million years old. Explain why carbon-14 could not be used to date it.
Show answer
65 000 000 ÷ 5730 ≈ 11 000 half-lives. After that many halvings there is effectively no carbon-14 left to measure. Scientists date fossils this old using isotopes with much longer half-lives, in the surrounding rocks.
6. Honey, I Shrunk the Kids – the shrinking machine
🎬 The scene: The kids wander into the attic and are accidentally zapped by Wayne’s shrinking machine.
Q1 (F) Most of the volume of an atom is what?
Show answer
Empty space. Almost all the mass is in a tiny nucleus in the centre.
Q2 (F/H) An atom has a radius of 1 × 10⁻¹⁰ m. The nucleus is about 10 000 times smaller. Calculate the radius of the nucleus.
Show answer
1 × 10⁻¹⁰ ÷ 10 000 = 1 × 10⁻¹⁴ m
Q3 (H) Which experiment showed that atoms are mostly empty space, and what was the key result?
Show answer
The alpha scattering experiment. Most alpha particles passed straight through gold foil, so the atom is mostly empty space. A few were deflected through large angles, showing a tiny, dense, positive nucleus.
7. The Incredible Hulk – the gamma experiment
🎬 The scene: The opening titles of The Incredible Hulk (2008) – Bruce Banner’s gamma radiation experiment goes wrong. (12A: some action.)
Q1 (F) What is gamma radiation?
Show answer
An electromagnetic wave given out by an unstable nucleus. It has no mass and no charge.
Q2 (F/H) Put alpha, beta and gamma in order from most to least penetrating, and say what stops each.
Show answer
Gamma (reduced by thick lead or concrete) → beta (stopped by a few mm of aluminium) → alpha (stopped by paper or a few cm of air).
Q3 (H) Real or fake? What would a large dose of gamma radiation really do to a person?
Show answer
It would ionise atoms in cells, damaging DNA. A large dose causes radiation sickness and can kill; lower doses increase the risk of cancer. It would not give superpowers. Fake!
8. Fantastic Four – the cosmic storm
🎬 The scene: A cosmic radiation storm hits the space station earlier than expected, exposing the crew (2005 film).
Q1 (F) Cosmic rays are one source of background radiation. Name two others.
Show answer
Any two: rocks and soil (e.g. radon gas), food and drink, medical X-rays and treatments, nuclear weapons testing, nuclear accidents.
Q2 (F/H) Why do astronauts receive a higher radiation dose than people on Earth?
Show answer
On Earth, the atmosphere absorbs most cosmic rays. In space there is no atmosphere to shield them.
Q3 (H) An astronaut receives about 0.5 mSv per day. How much is this over 180 days? How many times bigger is it than a typical UK yearly dose of 2.7 mSv?
Show answer
0.5 × 180 = 90 mSv. 90 ÷ 2.7 = about 33 times bigger.
9. Indiana Jones and the Kingdom of the Crystal Skull – the fridge
🎬 The scene: Indy finds himself in a test town minutes before an atomic bomb test – and hides in a lead-lined fridge. (12A: peril.)
Q1 (F) An atomic bomb uses nuclear fission. What is fission?
Show answer
A large, unstable nucleus (e.g. uranium-235) splits into two smaller nuclei, releasing energy.
Q2 (F/H) Describe a chain reaction. How is it kept under control in a nuclear power station?
Show answer
A neutron is absorbed by a uranium nucleus, which splits and releases two or three more neutrons. These cause more fissions, and so on. In a reactor, control rods absorb neutrons so only about one neutron from each fission causes another. In a bomb, it is uncontrolled.
Q3 (H) Real or fake? Could a fridge protect someone near a nuclear explosion? Think about the blast, heat and radiation.
Show answer
Fake. The thin metal wouldn’t stop gamma radiation or neutrons, the heat would be intense, and the impact of landing would be deadly. Afterwards, radioactive fallout would contaminate everything around him.
10. Spider-Man 2 – handling tritium with robotic arms
🎬 The scene: Before the experiment, Dr Octavius shows off the mechanical arms that let him handle the reactor’s fuel from a distance.
Q1 (F) Why might a scientist use remote arms to handle radioactive material?
Show answer
To keep a safe distance from the source and reduce their exposure to radiation.
Q2 (F/H) Tritium is an isotope of hydrogen with 1 proton and 2 neutrons. What are isotopes?
Show answer
Atoms of the same element with the same number of protons but a different number of neutrons.
Q3 (H) Tritium decays by beta emission. What happens in the nucleus, and what element does it become?
Show answer
A neutron changes into a proton and a high-speed electron (beta particle) is emitted. The atomic number goes up from 1 to 2, so it becomes helium (helium-3). The mass number stays at 3.
Teachers: the buttons open a YouTube search, so you can pick whichever upload is currently available. Please watch the clip through before showing it to a class.
