(a) Chemical Weathering results from chemical reactions between minerals in rocks and external agents like air or water. Oxygen oxidizes minerals to alteration products whereas water can convert minerals to clays or dissolve minerals completely.

chemical weathering

Mechanical weathering breaks rocks into smaller pieces without changing their composition. Ice wedging and abrasion are two important processes of mechanical weathering. Chemical weathering breaks down rocks by forming new minerals that are stable at the Earth’s surface.

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.

Weathering breaks down the Earth’s surface into smaller pieces. Those pieces are moved in a process called erosion, and deposited somewhere else. Weathering can be caused by wind, water, ice, plants, gravity, and changes in temperature.

Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. Once a rock has been broken down, a process called erosion transports the bits of rock and mineral away. No rock on Earth is hard enough to resist the forces of weathering and erosion.

Example of weathering: Wind and water cause small pieces of rock to break off at the side of a mountain. Weathering can occur due to chemical and mechanical processes. Erosion is the movement of particles away from their source. Example of erosion: Wind carries small pieces of rock away from the side of a mountain.

The negative effects of weathering and erosion on human lives are: Weathering damages national monuments, historical buildings and other imperfections to stone, marble, wood and other materials.

Positive Impacts • The weathering of rocks helps to form the basic component of soil. Soil is very essential for Human Activities . Negative Impacts • Erosion by flowing water during floods causes extensive damage to human properties and they also destroy lives. Floods can cause crops and livestock destruction.

Surface cover and runoff. Surface cover is a major factor to control erosion because it reduces the impact of raindrops falling on bare soils and wind removing soil particles. It also reduces the speed of water flowing over the land. Erosion risk is significantly reduced when there is more than 30% soil cover.

Landslides and soil erosion are two major effects of weathering.

Weathering gradually weakens rocks, and eventually produces new geological materials (rock fragments, sands, silts and clays) that are more stable in the new environment. Weathering generally produces finer and less dense rock materials, and weaker, more porous and permeable rock masses.

Answer: Weathering is a part of geomorphic process leading to the disintegration and decomposition of rocks and minerals on the earth’s surface as a result of physical and chemical action that leads to the formation of soil being a vital resource of rock weathering.

Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.

There are different types of chemical weathering processes, such as solution, hydration, hydrolysis, carbonation, oxidation, reduction, and chelation. Some of these reactions occur more easily when the water is slightly acidic.

(1) The physical process that causes the dissolution of calcium feldspar (1) is a process of hydrolysis corresponding to the replacement of a cation (Ca2+) on the mineral surface by a proton (H+). This first step in chemical weathering is the surface protonation of the mineral.

Acid rain is one way in which rocks can be chemically weathered. It can harm forests and crops, damage bodies of water, and contribute to the damage of statues and buildings. In this activity you will simulate the chemical weathering of limestone, which is a soft, sedimentary rock that reacts easily to acid rain.

Chemical weathering occurs when water dissolves minerals in a rock, producing new compounds. Hydrolysis occurs, for example, when water comes in contact with granite. Feldspar crystals inside the granite react chemically, forming clay minerals. The clay weakens the rock, making it more likely to break.

Answer: acid rain is the answer.

What is an example of Chemical Weathering. Acid rain raining on rocks and breaking it down from the reaction of the chemicals.

The major reactions involved in chemical weathering are oxidation, hydrolysis, and carbonation. Oxidation is a reaction with oxygen to form an oxide, hydrolysis is reaction with water, and carbonation is a reaction with CO2 to form a carbonate.

Examples of Chemical Erosion:

• Carbonation – When carbon dioxide is present and carried by water, carbonation weathering can occur.
• Hydration – This type of weathering occurs when rocks absorb water, and the resulting hydrogen and hydrate ions form new bonds with minerals present within the rock.

Oxygen directly participates in the chemical weathering of rocks through the process of oxidation. In this process, oxygen reacts with a substance within the rock and forms oxides which will result in weathering. The most common example of chemical weathering through oxidation is the rusting of iron.

Chemical weathering changes the composition of a mineral to break it down. Water chemically weathers rock in hydrolysis. Carbon dioxide chemically weathers rock by creating acids. Oxygen chemically weathers rock by combining with a metal.