The 4 main factors the determine the rate of weathering

CLIMATE: The amount of water in the air and the temperature of an area are both part of an area’s climate. Moisture speeds up chemical weathering. Weathering occurs fastest in hot, wet climates. It occurs very slowly in hot and dry climates. Without temperature changes, ice wedging cannot occur. In very cold, dry areas, there is little weathering. SURFACE AREA-
Most weathering occurs on exposed surfaces of rocks and minerals. The more surface area a rock has, the more quickly it will weather. When a block is cut into smaller pieces, it has more surface area. So, therefore, the smaller pieces of a rock will weather faster than a large block of rock ROCK COMPOSITION-
Some minerals resist weathering. Quartz is a mineral that weathers slowly. Rocks made up of minerals such as feldspar, calcite, and iron, weather more quickly. Pollution speeds up weathering. Factories and cars release carbon dioxide and other gases into the air. These gases dissolve in the rainwater, causing acid rain to form. Acid rain contains nitric and sulfuric acid, causing rocks and minerals to dissolve faster. 

Amethod of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.