Indiana Science HS-PSII-10.2
The Standard
Explain the stability of the nucleus considering the electromagnetic repulsion in the nucleus and how forces govern binding energy and radioactive decay for different elements.
Indiana Academic Standards for Science (2023) · Modern Physics
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students compare the repulsion between protons with the short-range force that holds protons and neutrons together. They use proton and neutron counts to explain why some nuclei stay intact while others decay. They connect binding energy and changes in mass to energy released during decay.
What Mastery Looks Like
- A student can identify carbon-12 as stable and carbon-14 as radioactive. They can explain that carbon-14 turns a neutron into a proton during beta decay, forming nitrogen-14. They can explain that decay releases energy when the products have less total mass.
Common Misconceptions
- Students may think electrons hold the nucleus together or that protons attract each other. Some think adding neutrons always makes a nucleus stable. Others think breaking any nucleus apart automatically releases energy.
How to Assess It
- Exit ticket: Why can uranium-238 emit an alpha particle? Ask students to mention proton repulsion, the short-range force holding the nucleus together, and where the released energy comes from.
Lesson moves
Ways to Teach It
Build carbon-12 and carbon-14 with red proton and blue neutron counters, then label proton repulsion and short-range attraction on each model.
Ask students to write why carbon-14 can become nitrogen-14 while carbon-12 remains stable, using neutron balance in their answer.
Give pairs carbon-12, carbon-14, and uranium-238 cards plus a decay chart; have them match each to no decay, beta decay, or alpha decay.
Show a photo of an americium-241 smoke alarm label and ask why its alpha particles come from nuclear decay, not burning.
Free download
Printable HS-PSII-10.2 Worksheet
A ready-to-print activity worksheet aligned to HS-PSII-10.2, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetKeep exploring
Related Standards
- HS-PSII-10.3
Qualitatively compare and contrast how particle interactions, fission, and fusion can convert matter into energy and energy into matter and calculate the relati...
- HS-PSII-10.4
Apply the conservation of mass, conservation of charge, and conservation of linear momentum principles to describe the results of a radioactive particle undergo...
Turn this exact standard into a lesson
Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.
Also for this standard:Make a WorksheetMake a QuizMake a Sub Lesson