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Accounting for partnership:basic concepts

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Class 10 Class 12

When α-particles are sent through a thin metal foil, most of them go straight through the foil. What inference do you draw from it?


There must be very large empty space within the atom.

Do protons and neutrons have identical mass?


No, neutron is slightly heavier than proton.

What is Plum-Pudding model of the atom?


J.J Thomson proposed that an atom possesses a spherical shape (radius approximately 10-10m) in which the positive charge is uniformly distributed. The electrons are embedded into it in such a manner as to give the most stable electrostatic arrangement. This model is known as Plum-pudding model of the atom.


Name a species which has
(i) no electron
(ii) no neutron.

(i) Proton
(ii) Protium left parenthesis left parenthesis straight H presubscript 1 presuperscript 1 right parenthesis.


What did Rutherford's experiment on scattering of particles show for the first time?


It showed for the first time that the atom has nucleus. The entire mass and the positive charge is concentrated in it.