Question

video topic 2 - hde chemistry & physics: history of the atom 1. what year was daltons model of the atom created? 2. from class, do you remember what daltons model was also called? 3. what kind of ray did thomson use in his experiments in 1800s? 4. what did thomson figure out? 5. what did rutherford shoot positive particles at? 6. what did rutherford figure out? 7. what was the problem with rutherfords model? 8. what did bohr figure out? 9. what do we know about the path of electrons? (can they be wherever they want?) 10. what model of the atom do we learn in class?

Explanation:

1. Dalton's atomic model was created in 1803.
2. Dalton's model was also called the solid - sphere model.
3. Thomson used cathode rays in his experiments in the 1800s.
4. Thomson discovered the electron.
5. Rutherford shot positive particles (alpha particles) at a thin gold foil.
6. Rutherford figured out that the atom has a small, dense, positively - charged nucleus.
7. The problem with Rutherford's model was that according to classical electromagnetic theory, the orbiting electrons should lose energy and spiral into the nucleus.
8. Bohr figured out that electrons orbit the nucleus in fixed energy levels or shells.
9. Electrons do not have a well - defined path in the sense of classical physics. They exist in probability clouds, not in fixed orbits where they can be anywhere they want in a non - deterministic way within certain regions.
10. A common model learned in class is the electron - cloud model which describes the probability of finding an electron in a certain region around the nucleus.

Answer:

1. 1803
2. Solid - sphere model
3. Cathode rays
4. Discovery of the electron
5. Thin gold foil
6. Atom has a small, dense, positively - charged nucleus
7. Orbiting electrons should lose energy and spiral into the nucleus according to classical electromagnetic theory
8. Electrons orbit the nucleus in fixed energy levels or shells
9. Exist in probability clouds, not in fixed orbits
10. Electron - cloud model