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Nuclear Decay

Akoranga 4: Mahi Tuatahi 🔗

Is it possible to turn copper into gold? Discuss with the person next to you!

Te Whāinga Ako 🔗

Pātai: What is a nuclear reaction? 🔗

Three Types of Nuclear Reactions 🔗

  1. Radioactive decay (alpha, beta, gamma emission)
  2. Fusion reaction
  3. Fission reaction

Radioactive Decay 🔗

Pātai: But why? 🔗

Some principles apply!


Polonium-211 is an unstable isotope and goes through alpha decay to become a more stable lead-207 isotope. It does this by emitting an alpha particle and energy.

Alpha Particle 🔗

Alpha Radiation 🔗


Hydrogen-3 goes through beta decay to become a more stable helium-3 atom. It does this by emitting beta particles.

Akoranga 5 Mahi Tuatahi 🔗

  1. Write the date in your books
  2. Try and remember, without using your books, what are three things that are conserved during radioactive decay?

Te Whāinga Ako 🔗

  1. Describe the three forms of radioactivity – Alpha, Beta and Gamma radiation.

Beta Radiation 🔗

Gamma Radiation 🔗

What would happen to each radiation type as it enters a magnetic field (coming out of the page) traveling from the left?

Pātai: What is nuclear radiation/materials used for? 🔗

Nuclear Reactors 🔗

Our current nuclear power reactors utilise nuclear fission of plutonium to create energy. Unfortunately they also produce radioactive by-products which are hard to dispose of in a safe way.

Steralisation 🔗

It can also be used to steralise a variety of medical instruments and food.


Tracers 🔗

It can also be used in medical imaging and tracers to follow the path of materials through an ecosystem.

Smoke Detectors 🔗

Inside an ionisation chamber, americium-241 decays through alpha decay. The alpha particles collide with the air molecules causing them to become ionized. Because they are now charged, current can be carried between the two plates inside the chamber.

Mahia Kāinga Booklet Q9 🔗