Final answer:
Water is the factor that contributes to both chemical and mechanical weathering, playing a significant role in the breakdown and transport of Earth materials, leading to soil formation and landscape shaping.
Step-by-step explanation:
The factor that contributes to both chemical and mechanical weathering is water. Water plays a crucial role in both processes: it is involved in the chemical breakdown of minerals through reactions like hydrolysis and hydration, and it also physically impacts rocks through processes like frost wedging, where water freezes and expands in cracks, causing the rock to break apart.
In addition to being a catalyst for oxidation reactions, water can also transport weathered materials, aiding in the formation of soil. The presence of water influences soil characteristics, and it's central to the erosion processes that shape the Earth's landscape. Collectively, these weathering and transporting are crucial for soil formation, affecting the soil horizons and leading to the creation of various sedimentary rocks.