Final answer:
Flakes of bricks are indicative of both mechanical and chemical weathering, with mechanical processes like temperature changes causing physical breakdown, and chemical reactions leading to changes on the brick's surface.
Step-by-step explanation:
Flakes of bricks, a result of both physical and chemical weathering, describe a process where rock material is broken down through various mechanisms. When bricks flake off, it's typically due to mechanical breakdown, like with other rocks that experience disintegration due to environmental factors such as temperature changes, ice formation, or abrasion. However, the efflorescence (white powder) that sometimes appears on bricks is a result of chemical reactions between brick constituents and the environment, pointing towards chemical weathering. Both mechanical and chemical weathering contribute to alterations in the rock and materials used in construction, such as bricks. Weathering is a key concept in geology and earth science, as it impacts soil formation and landscape changes.