Question

Explain how the series of experiments performed by Crookes, Thomson, Rutherford, and Chadwick represent the process of developing and refining a scientific theory.

Answer 1

This is a good question. Start with what is a scientific theory. You have a hypothesis, you perform experiments, you either validate your hypothesis with the data collected or you have to toss it. Thomson hypothesised that the atom was like a plum pudding with electrons studded in a mass of positive stuff. When Rutherford observed that most of the atom is empty - observed that most of alpha particles are undeflected, the figured out that thomson's hypothesis could not be true. So they tossed that one and created a new theory.

Answer 2

Crookes studied high-speed electrons. Electrons are not nuclear. Roentgen using Crookes' invention discovered X -rays which are nuclear. You may surmise about the relationship between
nuclear and non-nuclear. Very fast moving electrons interact with the nucleus to produce radiation.

Each experiment tells you something and directs you to the next step. Crookes' paradigm could possibly be thinking in terms of nuclear interaction. Using this thinking, you look at cosmic radiation which is fast-moving nuclei and ask:" Did they come from the action of fast-moving electrons striking the nucleus or by some other device?"

One Thomson proved the electron was a particle, the other Thomson proved it was a wave. Experimental confirmation of quantum mechanical wave-particle duality so the electron may be thought of of a particle or a wave. A wave of what? A wave of complex numbers.

Quantum-mechanical models make atomic models understandable and have been shown to be real.