BRAINLIEST! Write a short paragraph that explains the central idea of the article. Use at least two details from the article to support your response. A graphic showing illustrations of different types of weathering.
Graphic: Newsela staff

The Earth's surface is always changing because of weathering and erosion. Weathering breaks down rocks from large sizes to small particles. It is different from erosion because weather happens in place. Erosion, on the other hand, is what carries pieces away.

## Physical Weathering

Physical weathering happens when rocks wear away or crumble because of physical forces. The materials or chemicals that make up the rocks stay the same.

Extreme hot and cold temperatures can cause this type of weathering. For example, water seeps into cracks in rocks. As the water freezes, it expands. The ice breaks rocks by pushing against the inside of the rock. Wind is another example. Wind can blow sand against hard surfaces. As the sand and wind passes against landforms, it rubs away rocks like sandpaper.

## Chemical Weathering

Chemical weathering is another way rocks and landforms change. It happens when some type of chemical change happens. Water and the oxygen in air cause chemical weathering.

Rain, such as acid rain, eats away at certain types of rocks such as limestone, creating cracks and holes. Many caves form in limestone because of chemical weathering. The water dissolves limestone. The chemicals that make up limestone spread out evenly into water. It's similar to when salt dissolves in water. Then, some of the chemicals change into different ones.

Another example of chemical weathering is rust. Some rocks have iron in them that rust when exposed to oxygen. Rocks that have a lot of rust crumble apart easier.

## Biological weathering

Living things cause biological weathering, both physical and chemical. Plants can grow through cracks in rocks. As the plant grows, it pushes the rock apart and makes it weak. The rock wears away faster. Humans can also cause weathering. Hiking wears away rocks in trails. Animals dig and carve out spaces to live in.

Sometimes plants and animals release chemicals. It can eat away rocks and landforms.