The concept of the atom has changed dramatically over the years. Some of the more important models include the Plum Pudding Model, the Nuclear Model, the Bohr Model and the Quantum Mechanical Model. Why has the model changed over time?

As more experiments are done, and more experimental data are collected, scientific theories and models have to change to match the data.

The international scientific community periodically meets and votes to rename the model of the atom even though the model is not really changing.

Experiments show that the atom is changing as time passes just like the climate.