Q: What is the difference between weathering and erosion?

 Weathering is the process of decomposing, breaking up, or

changing the color of rocks. Weathering may be caused by the action of water, air, chemicals, plants, or animals.

 Chemical weathering involves chemical changes in the minerals of the rock, or on the surface of the rock, that make the rock change its shape or color. Carbon dioxide, oxygen, water, and acids may all cause chemical weathering.

Mechanical weathering is the process of breaking a large rock into smaller pieces

without changing the minerals in the rock. Mechanical weathering may be caused by frost, ice, plant roots, running water, or heat from the sun.

 Once the small pieces of rocks are changed or broken apart by weathering, they may start to be moved by wind, water, or ice. When the smaller rock pieces (now pebbles, sand or soil) are moved by these natural forces, it is called erosion.

  So, if a rock is changed or broken but stays where it is, it is called

weathering. If the pieces of weathered rock are moved away, it is called erosion.

Images for weathering and erosion:

 Weathering and Erosion  

Release of pressure from the rock