Final answer:
The questions pertain to a Mathematics or Geometry course focused on Modeling: Solids, likely in the context of physical chemistry involving phase transitions. Without access to the specific questions, assistance can be general, focusing on crystal structure, lattice energy, and phase transitions.
Step-by-step explanation:
The subject of the question refers to a practice exercise under the topic of Modeling: Solids from a Mathematics or Geometry course. Since the resources mentioned are related to Phase Transitions and general chemistry, the exercises likely involve applying mathematical concepts to physical chemistry problems, particularly the modeling of solids in various states or during phase transitions.
To begin to answer questions 3 and 4 in section 4.4.3, you would need to have access to the specific practice material which includes all the necessary details about the exercise. As a tutor, I would be able to assist if I can view the exact questions or problems. However, it is necessary to understand concepts such as crystal structure, lattice energy, and phase transitions when dealing with exercises on solids and their modeling.