Weathering

the breakdown of the materials of earth’s crust into smaller pieces

the breakdown of rocks involves a chemical change in at least some of the minerals within a rock; rainwater, oxygen, co2, plant decay acids

the breakdown of rocks caused by physical processes; only size changes

process by which rocks are broken down into smaller pieces by external conditions

mechanical weathering: as water freezes, it expands—placing pressure on the rock around it

mechanical weathering: rocks exfoliate, or break a part in laters as pressure from overlying rocks is reduced or removed

mechanical weathering: when plant roots grow into a rock or under a rock, they break rocks apart as they grow

mechanical weathering: friction and repeated impact by water, ice, or wind

mechanical weathering: animals in the ground burrow and break particles off of rocks

agents of chemical weathering: water weathers rock by decompressing, dissolving, or loosening parts of the rock

agents of chemical weathering: sometimes a change in the color of a rock is an indication that ____ has occurred; oxygen combines with other substances

agents of chemical weathering: occurs when co2 from the atmosphere slowly enters concrete over time, reacting with some of the reaction in the substances and water in the pores of the rock

agents of chemical weathering: plants that grow on rocks produce weak acids that chemically weather rocks

agents of chemical weathering: compounds from burning oil, coal, and gas react chemically with water, forming acids; very rapid chemical weathering