What is weathering?
1. Rocks are constantly...
2. As plant roots grow larger, they cause cracks in rocks to...
1. Changing
2. Widen and rocks break apart
A rock can break down when the minerals in the rock are...
Changed chemically
Soil is mostly bits of...
weathered rock, minerals, and humus
Freezing and thawing, plants, wind, and pressure can break rocks into...
smaller pieces
Decaying plants leave acid in soil that are dissolved by...
Water
Soil also contains...
Water, air, and bacteria
What involves ways that rock breaks down without changes to the chemicals they are made of
Physical weathering
Dissolved acids react when they come into contact with a rock's minerals and cause it to...
Change chemically
It can take how many of years for weathering to break rocks down to form soil
Thousands of years
1. The breaking down of rocks is called...
2.Over time, repeated what of water breaks rocks apart.
1. Weathering
2. Freezing and thawing
When what in air dissolves in water, it can react with iron in rocks to form rust and cause the rocks to break down
Oxygen
Soil layers are called horizons, and each has its own...
Properties
1.Outer layers of rock peel of like the layers of an onion in a kind of weathering called...
2. The wearing away of rock by wind is called...
1. Exfoliation
2. Abrasion
Carbonic acid that can react with the minerals in some rocks forms when carbon dioxide combines with...
Rainwater
Soil horizons are different from place to place because the what and what that make up soil are different from place to place.
Rocks and humus