NEET2026ChemistryChapterActual
In Rutherford's scattering experiment, which specific observation led to the conclusion that the entire positive charge and most of the mass of the atom are densely concentrated in an extremely small region?
Options
- AMost of the -particles passed straight through the metal foil without any deflection.
- BA very small fraction of the -particles bounced back, experiencing a deflection of nearly 180^ .
- CSome -particles were deflected by very small angles as they passed through the foil.
- DThe -particles produced bright flashes of light upon striking a fluorescent screen.
Correct answer
B. A very small fraction of the -particles bounced back, experiencing a deflection of nearly 180^ .
Step-by-step solution
In Rutherford's -particle scattering experiment, the observation that a very small fraction of the -particles (about 1 in 20,000 ) bounced back or were deflected by nearly 180^ indicated that they experienced a massive repulsive force. This strong repulsion could only occur if the entire positive charge and almost all the mass of the atom were concentrated in a very small, dense region at the center, which Rutherford called the nucleus. The observation that most particles passed straight through indicated that most