Question

1)Explain how different observations and experiments led to changes in the atomic model.

Answer 1

Describe the changes in the atomic model over time.
The existence of atoms began to be accepted around 1910 when many theories called upon the fact that atoms most exist (for example the work of Boltzmann trying to explain entropy, died 1906).
At that time atoms were seen as tiny small ball like objects, all matter was composed of. the models have been advanced ever since. Key names that are worth looking up are J. J. Thomson, Rutherford, Bohr and de Broglie.

Explain how different observations and experiments led to changes in the atomic model.
Many of the models that the men above proposed were created upon what they saw from their experiments. An example is that Niels Bohr wanted to explain the spectral lines in hydrogen, introducing the energy shells are quantized.

de Broglie saw that we could calculate wavelengths for particles with a certain velocity, introducing the particle wave duality.

Rutherford suggested that electrons are orbiting the nucleus like planets.

Thomson that there was a "electronsness" surrounding a positive core.

They can all be explain more deeply, but this is just introductory.