Chapter 13: Nuclei
NCERT Class 12 Physics, Part II, Chapter 13. 6 lessons, 15 narrated 3D videos, 7 simulations and 14 quiz questions, following the textbook section by section.
- Atomic masses and the nucleusBlow an atom up to the size of your classroom. The nucleus at its centre would be about the size of a pinhead. Yet that pinhead holds more than 99.9 per cent of the mass…
- Size of the nucleusRecall Rutherford’s experiment. Alpha particles fired at a thin gold foil. Most go straight through; a few bounce back from the tiny, positive gold nucleus.
- Mass–energy and binding energyBefore Einstein, we treated mass and energy as two separate things, each conserved on its own in any reaction.
- The nuclear forceA nucleus packs many protons into a space a few femtometres across. Every pair of those protons repels. So why does the nucleus not fly apart?
- Radioactivity and the decay lawYour NCERT book describes the three kinds of radioactive decay. The law of radioactive decay, in the next video, goes beyond the current syllabus, but it is useful, for…
- Nuclear energy: fission and fusionLook again at the binding energy curve. A long flat middle, near 8 MeV per nucleon, from A equals 30 to 170. Lower on both sides: for light nuclei below 30, and heavy…