Glossary of Terms. Bronchus / Bronchi / Bronchioles. The airways of the lungs. When a person takes in a breath of air, the air travels through the nose or mouth, into the larynx, then into the trachea, which is the main passageway into the lungs. The trachea divides into a right and left main bronchus.
Plant and animal life, atmosphere and water are the major causes of weathering. Weathering breaks down and loosens the surface minerals of rock so they can be transported away by agents of erosion such as water, wind and ice. There are two types of weathering: mechanical and chemical.
What Are the Four Causes of Mechanical Weathering? By Wayne Shirey; Updated April 24, 2017 The process of weathering breaks down rocks exposed to the elements into smaller particles that can be carried away by wind and water erosion. Weathering is divided into three broad categories: mechanical or physical weathering, chemical weathering, and biological weathering. Mechanical or physical weathering is further divided by its causes into four different categories; the causes are mechanical exfoliation or unloading, thermal expansion, frost wedging, and abrasion.