Description of Atomic Model: All matter is made of indivisible particles called atoms. All atoms of a given element are identical. The atoms of one element are different form those of another. Atoms combine in whole number ratios to form compounds. A chemical reaction is a separation, combination, or rearrangement of atoms.

Description of Experimental Design: If a stone were divided in half, the two halves would have essentially the same properties as the whole. If the stone were to be continually cut into smaller and smaller pieces then; at some point, there would be piece which would be so small as to be indivisible.

Conclusions: He had propose the idea of "atoms" .

Pros: First proposed atom, unique atoms for each element.

Cons: Macro properties having to much elements.

Description of Atomic Model: Electrons can gain and lose energy by jumping from one energy level to another. The energy levels of an atom are like the floors on a building. To move higher level, electron must absorb energy. When moving from a higher level to a lower one, the electron emit energy as photons of light.

Description of Experimental Design: Atoms are solid, homogeneous, indivisible, and indestructible. All matter consists of different types of atoms (different shapes and sizes). All particles is composed of tiny invisible particles called atoms.

Conclusions: Atoms are solid, indestructible units. All matter is composed of tiny invisible particles that are called atoms.

Pros: Roughly, spherical, limited amount of elements.

Cons: Doesn't tell us about the electrical nature of matter, continues atom.

Description of Atomic Model:

Drawing and Description of Experimental Design

Conclusions

Pros

Cons

Description- Alpha particles were emitted from the radioactive source and directed toward the gold foil. Most of the alpha particles passed through the foil, while some were deflected at various angles, and a few were reflected back toward the source.

Description of Experimental Design-alpha particles were directed at a thin gold foil. A fluorescent screen surrounding the foil detected the particles' deflections, showing that while most passed through, some were deflected at various angles.

Conclusions- atoms have a small, positively charged nucleus and are mostly empty space, leading to the adoption of the nuclear model over the plum pudding model.

Pros- Discovery of the nucleus, explanation of atomic structure.

Cons-The model could not explain why electrons don’t spiral into the nucleus, failed to account for quantized energy levels, and struggled with the complexities of larger atoms.

Description of Atomic Model

Electrons orbit the nucleus at certain specific distance and have specific energiesDrawing and Description of Experimental Design
When an electron is excited with energy the electron "jump" to a higher level and emits the energy the energy in the form of light when it falls back to its original level

Conclusions

-Electrons can gain and lose energy by jumping from one energy level to another

-Atoms move in orbit around the nucleusPros

Cons

He failed when he tried to expand and model atoms with more than one electron

Description of Atomic Model

-Electrons don't move in orbit, they move in waves and they don't exact location

Drawing and Description of Experimental Design
He use mathematical equations to describe the likelihood of finding an electron in a certain position

Conclusions

Developed the

quantum mechanical model of the

atom, which describes electrons

as wave functions rather than

fixed orbits, leading to the concept of electron clouds or orbitals.

Cons

hard to visualize

Description of Atomic Model

This model includes protons and neutrons (held together by the strong force) in the nucleus surrounded by electrons in cloud (orbitals)

Drawing and Description of Experimental Design

He placed polonium in a vacuum-sealed box, which radiated alpha particles through a piece of beryllium, which caused the unknown radiation to accelerate out

Conclusions

Discovered the

neutron, confirming that atoms

have a neutral particle in the nucleus along with protons, which helped explain atomic mass and stability.

Pros

explained missing mass

Cons

didn't take change atomic

model