Final answer:
As hydrogen atoms approach each other, their electron clouds overlap, leading to repulsion between electrons and attraction between electrons and the opposite atom's nucleus. These interactions can be depicted using Lewis diagrams.
Step-by-step explanation:
The molecular level picture illustrating what happens as approaching atoms begin to repel focuses on the interaction of subatomic particles. Initially, as hydrogen atoms approach each other, their electron clouds begin to overlap, which leads to two interactions: electron repulsion due to like charges and electron attraction to the opposite atom's nucleus. This duality affects the potential energy of the system, initially lowering it as stability increases. At the closest approach, the repulsion between positively charged nuclei starts to dominate, leading to an increase in potential energy and driving the atoms apart.
Electron clouds overlapping cause repulsion as well as attraction between electrons and the opposite nucleus. When the repulsion outweighs the attraction, atoms slow down and ultimately move apart. Chemists represent these interactions using Lewis diagrams which include the electrons and the nucleus, indicating the change in potential energy throughout the process with diagrams like in Figure 5.4.1.
The concepts from Figure 6.1.2 are relevant here, showing how molecular motion and freedom increase as attractive forces decrease from solid to gas phase. However, in this specific scenario, we are observing the opposite effect where increasing repulsive forces lead to an increase in distance between atoms, which also affects their potential energy and motion.