Acid rain is formed when certain pollutants, such as sulfur dioxide and nitrogen oxides, are released into the atmosphere and react with water, oxygen, and other chemicals to form acidic compounds. These compounds then fall to the ground as rain, snow, sleet, or fog, and can have harmful effects on the environment and human health.

The effects of acid rain include:

1. Damage to vegetation: High levels of acidity make it difficult for plants to absorb nutrients and can damage plant leaves and roots, leading to lower crop yields and deforestation.

2. Harm to aquatic life: Acid rain can lower the pH of bodies of water, which can be harmful to fish and other aquatic organisms.

3. Corrosion of buildings: Acid rain can cause damage to buildings, monuments, and other structures made of stone or metal, leading to costly repairs and maintenance.

4. Human health: Acid rain can worsen respiratory problems, such as asthma and bronchitis, and increase the risk of heart disease.

To prevent acid rain, it is important to reduce emissions of sulfur dioxide and nitrogen oxides from sources such as power plants, factories, and automobiles. This can be achieved through the use of cleaner technologies and alternative sources of energy, such as wind and solar power.