Final answer:
The fogging of a mirror involves water vapor particles condensing upon the cooler mirror surface, losing energy and forming a film that scatters light.
Step-by-step explanation:
The consensus model of matter includes the ideas that matter is composed of particles, these particles are in constant motion, the particles interact with each other, and the energy of particles increases with temperature. These concepts apply to a mirror fogging up as follows:
Interaction: Upon contact, the water vapor particles condense on the mirror due to interactions with the cooler surface.
When someone takes a hot shower, the bathroom fills with water vapor. The mirror's cooler surface causes the water vapor particles, which are in motion and interacting with each other, to lose energy and condense. This condensation forms a thin film of water, which scatters light, causing the mirror to fog up and become less reflective.