How is mechanical weathering best described a. the buildup of chemical deposits on the surface b. the breakdown of rock through mechanical disintegration and physical stress c. the build up of rock formations overtime d. the breakdown of rock through decomposition of chemicals

Option (B)

Explanation:

The mechanical weathering refers to the break down of rocks into smaller particles or sediments by the physical processes. This takes place in the terrestrial areas. The temperature and rainfall plays an essential role in controlling the rate of mechanical weathering. They are also known as physical weathering.

The mechanical weathering process takes place in different ways-

(1) In the region where the temperature is relatively cold, the rocks that are comprised of fractures traps water in it during the day time and at night the water in these fractures gets frozen. As a result of this, the volume of water in the ice increases by about 9%, and it exerts a pressure on the sides of the rocks due to which the rock breaks. This process is known as the freeze and thaw method.

(2) In the places where there is maximum rainfall and temperature, the rocks get affected. The water and the wind flows over the rock surface, and due to the abrasion process, the rocks are eroded by water and wind respectively.

(3) In the regions where temperature changes occur frequently, the rocks undergo expansion in the day time due to high temperature and undergo contraction in the nighttime due to low temperature. Due to this continuous expansion and contraction process, the rocks are weathered.

Thus, the process of breaking down of rocks due to the physical processes is known as the mechanical weathering process.

Hence, the correct answer is option (B).

a time line cause it goes from 685 to 978

lysosome is this part of the cell is surrounded by a very thick outer membrane to protect the rest of the cell from its strong enzymes.