Slides
Lesson slides
Slides for the lesson
Open resourceLesson 03
Decay Equations
Use decay equations to represent changes during radioactive emission.
Objectives
Lesson outcomes
- Write balanced nuclear equations for alpha, beta, and gamma emissions.
- Use conservation of nucleon number and proton number to complete missing particles or daughter nuclei.
- Interpret nuclide notation accurately when identifying the radiation emitted.
Syllabus
CIE 0625 syllabus points
5 linked
- 5.1.2.6 Describe the processes of nuclear fission and nuclear fusion as the splitting or joining of nuclei, to include the nuclide equation and qualitative description of mass and energy changes without values
- 5.2.2.4 Explain their relative ionising effects with reference to: (a) kinetic energy (b) electric charge
- 5.2.3.2 State that during α-decay or β-decay, the nucleus changes to that of a different element
- 5.2.3.4 Describe the effect of α-decay, β-decay and γ-emissions on the nucleus, including an increase in stability and a reduction in the number of excess neutrons; the following change in the nucleus occurs during β-emission neutron → proton + electron
- 5.2.3.5 Use decay equations, using nuclide notation, to show the emission of α-particles, β-particles and γ-radiation
Definitions
Required definitions
Nuclear fission
a process where a nucleus splits into two or more smaller nuclei.
Nuclear fusion
a process where light nuclei join to form a heavier nucleus.
Lesson Notes
Student guidance and lesson notes
Overview
Keep conservation of number and charge explicit in every worked example.
What You Need to Know
- Use decay equations to represent changes during radioactive emission.
- Identify the key definitions, models, equations, or diagrams for this lesson.
- Use at least one worked example, observation, or practical link to make the idea concrete.
How to Work Through It
- Start with the prior knowledge, context, or recall questions for this lesson.
- Work through the main explanation, method, diagram, or calculation for this lesson.
- Complete the guided practice, discussion, calculations, or practical application.
- Review your learning with an exit prompt, short question, or summary task.
Check Your Understanding
- Can you answer a checkpoint question aligned to the main objective(s)?
- Can you give a short verbal, written, or numerical response that shows secure understanding?
Common Mistakes
- Watch out for the likely misconception, error, or weak step in this lesson.
- Use the comparison, model answer, or explanation that corrects it.
Next Steps
- Complete the homework, retrieval task, or resource revisit linked to this lesson.
- Note what you need to carry forward into the next lesson.
Lesson Resources
Materials for this lesson
Use these videos, slide decks, documents, or links to work through the lesson.