Question

State the observations in alpha particle scattering experiment which lead Rutherford to make the following conclusion
Whole mass of an atom is concentrated at its centre

Answer 1

Practical observation
leads to the conclusion that most of mass is concentrated in nucleus
Most of alpha particles pass straight the atom only 1 in 20000 is reflected at an angle of 180° which made sure that there is mass concentrated in center.

Answer 2

The observations of Rutherford's experiment were as follows :-

• Most of the fast moving alpha particles passed straight through the gold foil.
• Some of the alpha particles were deflected by foil by small angles.
• Surprisingly one out of every 12000 particles appeared to rebound.
=> These observations lead Rutherford to make the conclusion that ' while mass of an atom is concentrated in its centre. '

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