These questions concern the work of J. J. Thomson. a. From Thomson’s work, which particles do you think he would feel are most important for the formation of compounds (chemical changes) and why? b. Of the remaining two subatomic particles, which do you place second in importance for forming compounds and why? c. Propose three models that explain Thomson’s findings and evaluate them. To be complete you should include Thomson’s findings.

J. J. Thomson was a British physicist who is credited with the discovery of the electron. His experiments with cathode rays led him to conclude that these rays were made of negatively charged particles that were much smaller than atoms. He dubbed these particles "corpuscles," which are now known as electrons. Thomson's work was also essential in understanding the atomic structure, leading to the development of the plum pudding model.

Thomson would likely believe that electrons are the most important particles for the formation of compounds. This is because electrons are involved in chemical bonding, which is essential for creating compounds. The negatively charged electrons are attracted to the positive nuclei of other atoms, forming chemical bonds that hold atoms together in compounds.

Of the remaining two subatomic particles (protons and neutrons), protons would likely be considered the second most important for forming compounds. The positively charged protons in an atom's nucleus determine the atom's identity (which element it is) and help to balance the negative charge from electrons. As a result, the number of protons plays a crucial role in determining how an atom bonds with other atoms to form compounds.

1. Plum Pudding Model: Thomson proposed the plum pudding model, which describes the atom as a positively charged sphere with electrons embedded throughout like plums in a pudding. This model explained the presence of electrons, that they are attracted to positive charges in chemical bonding. However, it failed to account for the presence of protons and the overall structure of the atom. 2. Rutherford's Nuclear Model: Rutherford's model, also known as the planetary model, was built on Thomson's findings. The model suggested that the atom consists of a small, dense, positively charged nucleus containing protons, with electrons orbiting around it. This successfully explains the observed behavior of electrons in chemical bonding and the importance of protons in compound formation. However, it didn't explain the presence and role of neutrons. 3. Bohr's Atomic Model: Bohr expanded on Rutherford's model by proposing specific energy levels for electrons orbiting the nucleus. Electrons could only exist in these specific energy levels, and the movement between levels while emitting or absorbing energy explained chemical reactions and bond formation. This model accurately incorporated Thomson's findings and explained the formation and behavior of compounds. Energy level theory has become more advanced since Bohr's time, but his model laid the foundation for the modern understanding of atoms.