There was no model made, Democritus just introduced the concept for the atom "atomos". His idea was unable to be conceptualized.

Image of Model: N/A

Experiment Conclusions:

Democritus came up with the concept that all matter is made up of small particles called atoms "atomos" which means indivisible, apart from this, atoms can not be created of destroyed. He did not use any material because he just came up with the idea and didn't follow through with an experiment.

Pros:

Democritus began the idea of the atom which makes up all matter, this would later become the foundation for scientists studying the atom in the future. Democritus also stated that atoms are indivisible and cannot be created or destroyed which helped Dalton with his atomic theory.

Cons:

Democritus was not able to make a model of his idea and he was very vague with his explanation due to lack of research and support by other philosophers.

Conclusion: About 400 B.C. the Greek philosopher Democritus suggested that all matter was formed of different types of tiny discrete particles and that the properties of these particles also determined the properties of matter.

Dalton's Solid Sphere Model

Experiment Conclusions

According to the Solid Sphere Model:
Dalton's Solid Sphere Model represents one of the earliest attempts to understand the fundamental nature of matter at the atomic level. Nevertheless, it is essential to emphasize that this model has been surpassed by more modern atomic models, including the Bohr model and the Quantum Mechanical Model. Dalton used oxygen for his experiment and other gases.

Pros :

One of the main pros of this model being that it was simple and not complex. Dalton's model was simple and easy to understand. It proposed that atoms were tiny, indivisible,and solid spheres with no internal structure.

Cons:

One of the main cons about this model it's that it's outdated. As the model is fundamentally flawed as it suggests that atoms are indivisible and solid spheres, which we now know to be incorrect. Atoms are composed of subatomic particles (protons, neutrons, and electrons) and have a complex internal structure.

Conclusion: John Dalton (1766-1844) was an English chemist, physicist, and meteorologist, best known for introducing the atomic theory into chemistry and for his work on human optics.

Experiment Conclusions:Plum Pudding Model conclude in the that (atoms, electrons, and protons) don't have define place they are just there lake a mass for example a cookie because is not a define shape and chocolate chps don't have a define place. For conclude from the cathode ray tube experiment that the atom can be divided into smaller particles.

Pros:the 3 best way to explain the pros of J.J. Thomson model are the next ones.

-It successfully explained electron neutrality of an atom

-It was the first atomic model which was simple and visual

-Was easy to explain's in vase of the water melon

Cons: In the other hand J.J. Thomson until was maybe easy to explain was missing some factors...

-Most of the space in an atom is empty

-One of the major drawbacks of his model is that there were no experimental pieces of evidence provided by him

-In this model there was no mention of the nucleus of an atom

Nuclear model / Rutherford's model

Experiment Conclusions:

According to the Rutherford atomic model using gold foil and alpha particles: The positive charge and most of the mass of an atom is concentrated in an extremely small volume. He called this region of the atom as a nucleus. Rutherford's model proposed that the negatively charged electrons surround the nucleus of an atom.

Pros:

He imagined electrons revolving around the nucleus like planets around the sun. He assumed most of the atoms were hollow.

Cons:

This atomic model failed to explain the stability of atoms, According to the model, electrons revolve around the positively charged nucleus, and this model of the atom also failed to explain the existence of definite lines in the hydrogen spectrum.

SITES: https://byjus.com/chemistry/rutherfords-model-of-atoms-and-its-limitations/#:~:text=According%20to%20the%20Rutherford%20atomic,the%20nucleus%20of%20an%20atom.

https://unacademy.com/content/neet-ug/study-material/physics/rutherford-atomic-model/#:~:text=Advantages%20of%20Rutherford%20model&text=He%20imagined%20electrons%20revolving%20around,known%20to%20be%20electrically%20neutral.

Planetary Model

Experiment Conclusions:

He used atomic emission spectrum of Hydrogen. He concluded that the electrons will have more energy if it is located further away from the nucleus but when the the electrons are closer to the nucleus they will have less energy.

Bohr model of an atom: This model represents that the electrons travel around the nucleus of an atom in distinct circular orbits, or shells.

Pros:

One of the main advantages of Bohr model is that it had the ability to explain the atomic emission spectra observed in experiments. It also allowed the calculation of energy levels for electrons in hydrogen and hydrogen-like atoms. As well, it introduced the concept of stable electron orbits.

Cons:

One of the main disadvantages of Bohr model is that it struggled to explain the behavior of multi-electron due to the complexities arising from electron-electron interactions and the presence of more intricate energy levels.

Schrödinger Quantum Mechanical Model

Experiment Conclusions:

The Schrödinger Quantum Mechanical Model, often referred to as the Schrödinger Wave Equation, serves as a foundational theory of quantum mechanics. It provides a comprehensive description of the behavior of particles at both the atomic and subatomic scales.

Pros:One of the pros to Schrödinger's model being that it provides a highly accurate predictions of the behavior of electrons in atoms and molecules.

Cons: One of the main cons of this model being that in many cases, exact solutions to the Schrödinger equation are not feasible, and approximations must be made. These approximations may introduce errors in predictions.

Chadwick's Quantum Mechanical Model / Chadwick's Atomic Model

Experiment Conclusions:

James Chadwick used Beryllium and bombarded it with alpha particles. He discovered that there was actually a neutral particle in the nucleus, the neutron. He also concluded that the mass of the neutron was very similar to the one of a proton only differing by 0.1 percent.

Pros :

He discovered that the nucleus contained another subatomic particle that held no charge, the neutron. He changed the way the nucleus was modeled and it helped create one of the most accurate atomic models.

Cons:

Chadwick's model lacked specific information about electrons like the electron cloud since he focused more on the nucleus. In his model he also made the atomic structure and behavior look less complex making it slightly inaccurate.

• https://www.collimator.ai/reference-guides/what-is-the-schrodinger-equation

• Pros: https://study.com/learn/lesson/the-quantum-mechanical-model-definition-overview.html

• Cons: https://www.sciencedirect.com/topics/physics-and-astronomy/schroedinger-equation

Democritus

• https://www.ucl.ac.uk/~ucfbasc/Basic/Atheory.html#:~:text=About%20400%20B.C.%20the%20Greek,determined%20the%20properties%20of%20matter.

• https://www.famousscientists.org/democritus/

J.J. Thomson

• https://www.khanacademy.org/science/chemistry/electronic-structure-of-atoms/history-of-atomic-structure/a/discovery-of-the-electron-and-nucleus#:~:text=Summary-,J.J.,positively%2Dcharged%20%22soup.%22

Ernest Rutherford

• https://www.khanacademy.org/science/chemistry/electronic-structure-of-atoms/history-of-atomic-structure/v/rutherfords-gold-foil-experiment

Niels Bohr

• https://www.britannica.com/science/Bohr-model

James Chadwick

• https://www.famousscientists.org/james-chadwick/

In general

• https://www.famousscientists.org