1. Models of the atom
Atomic Theory

2. Resources http://www.commonsensescience.org/atom_models.html
We will learn the following models:
Democritus’ model
Dalton’s atomic theory
Thomson’s model
Rutherford’s model
Bohr’s model
Combination of de Broglie, Shrodinger, and Standard Model of elementary particles.
Sketch, from the description, what each different model of the atom will look like.

3. Democritus’ model of the atom
“Our English word ‘atom’ comes from a Greek word ‘atomos’ meaning the smallest unit of matter. Democritus, a Greek philosopher of the late 5th century BC, taught that the smallest unit of matter, the atom, was irreducible and indestructible. ‘They believed that everything in the universe was composed of atoms.... There were an infinite number of atoms.... Atoms differed as to their size, shape, and perhaps their weight.’
Democritus came to their opinions about atoms by means of deduction: They knew that materials on earth, such as rocks, water or sand, are stable. For example, rocks don't just appear and then disappear. The early Greek scientists also could see that if they broke a piece of gold into two pieces, it was still gold (same color, soft metal, etc.).
But they asked, how small could a piece of gold become by repeated breaking and still remain gold? They deduced that when it became as small as a single atom, it would still be gold. But if anyone could break that single atom into smaller pieces, the gold atom would cease to exist. And we know that if there was anything left, it certainly wouldn't be gold.”

4. Dalton’s atomic theory
(Textbook p.68-69)
John Dalton, in 1808, proposed an explanation for the law of conservation of mass, etc. He made the first atomic theory:
All matter is composed of extremely small particles called atoms.
Atoms of a given element are identical in size, mass, and other properties; other elements are different in these properties.
Atoms can not be subdivided, created, or destroyed.
Atoms of different elements combine in simple whole-number ratios to form chemical compounds.
In chemical reactions, atoms are combined, separated, or rearranged.
Dalton turned Democritus’ idea into a scientific theory by making it measurable with the law of conservation of mass. However, not all points of Dalton’s theory are correct, and modern theories modify points 2 and 3 of this atomic theory.

5. Thomson’s model of the atom
“In 1897, J. J. Thomson showed by his famous experiment that there were small charged particles; today we call these particles electrons.
By 1904, Thomson “developed the picture of an atom as a sphere of positive charge, occupying the whole volume of the atom, with electrons embedded in it.”
Thomson's atom was able to explain some chemical properties of the many kinds of atoms known at this time (less than 100). The Thomson model of the atom had to be abandoned, however, because new experiments showed that at least most of the positive charge (from protons) was concentrated in the center of the atom, not over the entire volume.”

6. Rutherford’s model of the atom
“In 1911 Rutherford put forward the hypotheses that the positive charge of the atom was concentrated in a very small volume...within the nucleus.” In this model, the electrons were scattered around the volume of the atom outside the nucleus.
Gold foil experiment (textbook p.74)
Find what he did (procedure), and the conclusion

7. Bohr’s model of the atom
“In 1913, Niels Bohr proposed a theory of the hydrogen atom (the most simple of all atoms) consisting of one heavy proton in the center with one lighter electron in orbit around the proton. Bohr supposed
That electrons move in circular orbits around the atomic nucleus.
Only certain orbits are permitted.
That in these permitted orbits, the electrons would not radiate (would not create radio waves).
That light of certain colors (and wavelengths) would be created when the electron (of its own power) changed orbits. (emission line spectrum)
These postulates were entirely arbitrary and even violated the established laws of electricity and magnetism. In spite of this, physicists still use the Bohr model (when it is convenient).”

8. Modern model of the atom -DeBroglie and Schrodinger
De Broglie's Model of Matter: Particle-Wave Duality “About 1924, Louis de Broglie proposed that all particles of matter (from single atoms to large objects) moving at some velocity would have the properties of a wave. Today, most physicists take this farther and say that all material objects actually are waves until they are measured or observed in some way. When this takes place, the wave is said to collapse and turn into an object. An example of this notion of reality is given by the famous Cornell physicist N. David Mermin who says "We now know that moon is demonstrably not there when nobody looks.“
Schrodinger's Wave Model of the Atom “"In 1925, soon after de Broglie had put forward his ideas, Schrodinger used them [to write] a wave equation to describe this new mechanics of particles." Schrodinger's model of the atom is not a physical model (where an object has size, shape and boundaries) but is a mathematical model (an equation where objects are point particles.) The equation is useful to predict some properties of objects (or atoms), but is not able to describe the object (or atom) itself.

9. Standard Model (Quantum theory)
Standard Model of Elementary Particles “The Standard Model of Elementary Particles is not a description of the atom. However, we must mention it now because in modern theory, atoms are not only waves, but when measured the atoms change into objects composed of elementary particles. In modern physics, the important components of the atoms are electrons, protons, and neutrons.
The Standard Model considers electrons to be true elementary particles, either waves or point particles with inherent properties of mass, magnetism, spin and stability.
But in modern Quantum Theory, protons are supposed to be composed of quarks; and neutrons are thought to be composed of a different combination of quarks.
Another important part of the Standard Model is that forces between these elementary particles are supposed to be carried by other particles that move back and force randomly between the material particles:
photons are supposed to be particles that carry forces between electrons,
mesons are supposed to be particles that carry forces between protons and neutrons,
gluons are supposed to be particles that carry forces between the quarks (which are supposed to be inside protons and neutrons).”

10. Evolution of models of the atom

11. Explanation of illustrations