CBSE Class 12 Physics – Nuclei

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Study Materials

12th

12th - Physics

Nuclei

Chapter Overview

This chapter dives into the core of atoms – the nucleus. It covers nuclear composition (protons and neutrons), nuclear size, density, and structure. You’ll explore mass defect and binding energy, nuclear forces that bind nucleons together, radioactivity and decay laws, and energy-releasing reactions like fission and fusion. The chapter also links nuclear science with real-life applications in power generation, medicine, and archaeology.

Important Keywords

  • Atomic Number (Z): Number of protons in a nucleus.
  • Mass Number (A): Total number of protons and neutrons (nucleons).
  • Isotopes: Atoms with same Z but different A.
  • Mass Defect (Δm): Difference between mass of nucleons and actual nuclear mass.
  • Binding Energy: Energy required to disassemble a nucleus into its separate nucleons.
  • Nuclear Force: Short-range force holding protons and neutrons together.
  • Radioactivity: Spontaneous emission of radiation by unstable nuclei.
  • Decay Constant (λ): Probability of decay per unit time.
  • Half-life (T1/2): Time taken for half of the radioactive nuclei to decay.
  • Fission: Splitting of a heavy nucleus into lighter nuclei with energy release.
  • Fusion: Combining of light nuclei into heavier ones with energy release.

Detailed Notes

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