Nuclear atom, nuclides and amount

Repair the common break

Common misconception: Isotopes have different proton numbers.

Correct model: Rutherford scattering supports a small dense nucleus; isotopes share proton number but differ in neutron number, and amount links to Avogadro’s constant.

Worked transfer

Large-angle alpha deflections are rare, implying a very small, dense, positively charged nucleus. Nuclides with the same proton number but different neutron numbers are isotopes.

Guided practice

Explain why “Isotopes have different proton numbers.” fails. Then construct one example that correctly applies nuclear atom, nuclides and amount.

Independent practice

Use Rutherford-scattering observations to distinguish what establishes nuclear size, positive charge and mostly empty atomic space.

Return to the recorded repair plan when the explanation and application are secure enough to re-test.