Question

explain why did Rutherford practical file in Alpha scattering experiment what observation in Alpha scattering let Rutherford to make the following observation=
1) most of the space in an atom is empty
2) nucleus is positively charge
3) mention any two drawbacks of Rutherford model

Answer 1

Ernest Rutherford was interested in knowing how the electrons are arranged within an atom. Rutherford designed an experiment for this. In this experiment, fast moving alpha (α)-particles were made to fall on a thin gold foil.

He selected a gold foil because he wanted as thin a layer as possible. This gold foil was about 1000 atoms thick.

α-particles are doubly-charged helium ions. Since they have a mass of 4µ, the fast-moving α-particles have a considerable amount of energy.  

It was expected that α-particles would be deflected by the sub-atomic particles in the gold atoms. Since the α-particles were much heavier than the protons, he did not expect to see large deflections. But, the α-particle scattering experiment gave totally unexpected results .

Observations of Rutherford's scattering experiment:

1. Most of the fast moving α-particles passed straight through the gold foil.

2. Some of the α-particles were deflected by the foil by small angles.

3. Surprisingly one out of every 12,000 alpha particles appeared to rebound

Answer 2

As the nucleus is positively charged some particles make that that particles he discovered as alpha particles