Atomic Models
How to distinguish between these models?
Ernest Rutherford had discovered that certain rays given off by radioactive material were “? rays” - positive particles (ions) with the mass He atom.
Used to study the atoms itself! Observe how ? particles (Helium ions) scatter from a Gold foil.
Count the number of times an ? particle scatters through an angle ?, for different angles ?.
What do you expect?
- Plum Pudding: only small deflections since ? particles much heavier than electrons.
- Planetary: can occasionally get large deflections if most of the mass of the atom resides in the nucleus.