Rainwater that contains sulphur dioxide and other pollutants.
Sulphur and nitrogen oxides (released into the atmosphere by heavy industry and auto emissions) transform into acids, which fall to earth in rain and snow.
Rain and other precipitation, such as snow, sleet, or hail, that has a high acid content.
A term in common use that implies the deposition of acid materials in wet precipitation (rain, snow, fog) as well as in the dry precipitation of dust and gases. One source is the combining of rain and sulphur dioxide emissions – a by-product of combustion of fossil fuels.
Oxides of sulfur and nitrogen, often released as byproduct of coal combustion, combine with hydrogen ions from atmospheric moisture and oxidize during long range, high altitude movement, forming acidic (low pH) compounds which fall in rain or snow.
Abnormally acidic rainfall, most often containing dilute concentrations of sulfuric acid or nitric acid.
Rain with a very low pH caused by a combination of rain water with Sulfur and Nitrogen mostly from Pollution. Acid Rain has killed and is killing our lakes by lower their pH and leaching Mercury and other heavy metals from the soil into them.
Rain with a very low pH (often below 4.0) resulting from emissions to the atmosphere of oxides of sulfur and nitrogen.
Rainfall with a pH of less than 7.0. One source is the combining of rain and sulphur dioxide emissions, which are a by-product of combustion of fossil fuels. Also referred to as acid deposition and wet deposition.
Rain which is corrosive and causes environmental destruction.
precipitation having a pH value less than that of "normal" rainfall (5-5.6 average). Pure water has a pH of less than 7 due to the presence of dissolved gasses. Acid rain is caused mainly by the burning of fossil fuels such as oil and coal and from exhaust gas from cars and trucks.
Precipitation in which air pollutants react with water to make a weak acid that then falls from the sky.
Rainfall occurring when atmospheric water vapor combines with oxides of sulfur and nitrogen to form sulfuric acid or nitric acid.
Rain contaminated with absorbed acidic gases, such as sulphur dioxide, emitted into the atmosphere by activities such as fossil fuel burning.
Cloud or rain droplets containing pollutants, such as oxides of sulfur and nitrogen, to make them acidic (eg. pH 7.0). 7.0)
The deposition on land and water of strong acids (H2SO4, HNO3) in the form of rain, snow, fog, cloud water, and dry deposition. These acids are formed by the oxidation of SO2 and NOX emitted to the atmosphere during the combustion of fossil fuels. See Bricker and Rice (1993).
Rain water that has been contaminated with chemicals introduced into the atmosphere through industrial, automobile, and/or other emissions, causing the acidity of the rain to be increased from that of unaffected rain water.
rain that has been polluted by chemicals, mainly sulphor dioxide from factories and power station.
Happosade Surt regn Rain water pH is on the acidic side. Water containing nitric acid for example.
rainwater having a low pH as a result of air pollution
rain which contains dilute acids as a result of emissions of sulphur dioxide and other gases from factories, automobile engines etc.
Precipitation that becomes acidic due to acid-forming precursors put into the atmosphere by human activities.
Natural rainfall which contains nitric and sulfuric acids due to oxides of nitrogen and sulfur dioxide discharged into the air by industries, power plants, and automobiles.
rain that damages tress and plants because it contains acid that industries release into the air ..... return
Rain that has become more acidic than normal (a pH below 5.0) as certain oxides present as airborne pollutants are absorbed by the water droplets. The term is often applied generically to all acidic precipitation.
Precipitation that is contaminated with acid due to sulfur dioxide and oxides of nitrogen in the air.
When air pollutants from factories and the burning of fossil fuels dissolve in water, the resulting ‘acid rain’ falls on forests, killing trees and wildlife and seriously affecting soils. Acid rain is not a new phenomenon; all rainfall has a natural acidity, but pollution in the atmosphere increases this acidity more than a thousand times. And acid rain not only affects habitats when it falls as rain; acidity can also be present, and be just as damaging, in snow, hail, cloud, fog, mist, or even airborne dust. Adverse effects of climate change - means changes in the physical environment or biota resulting from climate change which have significant deleterious effects on the composition, resilience or productivity of natural and managed ecosystems or on the operation of socioeconomic systems or on human health and welfare.
rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water
Acid rain is not very dangerous for humans, however it can cause the death of plants, and in particular trees. This may be important because trees take in alot of Carbon Dioxide from the atmosphere (and produce Oxygen). If many trees died, then there would be more Carbon Dioxide left in the atmosphere - Carbon Dioxide is a Greenhouse Gas.
precipitation with a high concentration of acids from pollutants (such as sulfur dioxide and nitrogen oxide) that are emitted during the burning of fossil fuels in industry or vehicles; acid rain has a destructive effect on plant and animal life and buildings
is a rainfall with a lower than normal pH.Acid rain can cause reproductive failure in aquatic wildlife, damage vegetation and increase the rate that heavy metals such as lead are leached from the soil
Acid rain is rain, that is acidified in the atmosphere and can be damaging to the environment. Two common air pollutants acidify rain: sulphur dioxide (SO2) and nitrogen oxides (NOX). When these substances are released into the atmosphere, they can be carried over long distances by prevailing winds before returning to earth as acidic rain, snow, fog or dust. When the environment cannot neutralize the acid being deposited, damage occurs.
precipitation with a pH below 5.6.
an unnatural type of rain which occurs when sulfur and nitrogen compounds combine with raindrops to create nitric and sulphuric acids. This causes great damage to the environment and to man-made structures, especially concrete. It is common in the northeastern portion of North America, as the prevailing westerly winds carry pollution from the American midwest to the northestern United States and the lower portions of Canada. It also occurs downwind of many other industrialized areas of the world.
Rain with a high level of acidity caused generally by pollution by oxides of nitrogen and sulphur produced by coal and oil combustion. The oxides combine with water in the atmosphere forming acids such as nitric and sulphuric acids. Acid rain has caused the deaths of countless living organisms both by producing a high level acidity and by leaching metal ions from the soil into rivers and lakes. The effects can be disastrous to all ecosystems.
Rain, snow, hail and fog which is acidic, as a result of pollution. Acid rain has a pH lower than 7.
Rainwater that contains sulfur dioxide and other pollutants from industrial plants. There has been considerable damage done to the forests of the US and Canada.
Rain with pH values less than 6.
Rain containing chemical substances that are contributing to the acidification of the environment.
Commonly used to mean the deposition of acidic components in rain, snow, fog or dew. The extra acidity in rain comes from the reaction of air pollutants, primarily sulfur oxides and nitrogen oxides, with water in the air to form strong acids (like sulfuric and nitric acid). The main sources of these pollutants are vehicles and industrial or power-generating plants.
Moisture in the air (rain, dew, fog) traps airborne chemicals, creating a mild solution of hydrochloric acid. If acid rain falls or collects on your car, and the water dries in the warm sun, the concentration of acid increases and eventually etches your paint (creates small circular marks). Unless very severe, acid rain spots can be removed by polishing the paint.
Rain that contains dissolved acidic gases such as nitrogen oxides and sulphur dioxide. Energy
a term referring to acid falling to earth in rain, snow, frost, fog, mist, and gases or as dry particles. Acid rain is caused when sulfur dioxide and nitrogen oxides emitted into the atmosphere become acid through chemical reactions and then fall to earth.
Any kind of precipitation that is acid
rainwater with an acidic pH, a result of air pollution by sulfur dioxide and nitrogen oxides.
Sulfur dioxide emissions combining with water in the atmosphere and falling to the earth.
rain that has become acidic after contact with certain atmospheric gases (primarily sulfur dioxide, carbon dioxide, and nitrogen oxides).
Source: Economics: Principles & Practices Definition: pollution in form of rainwater mixed with sulfur dioxide, a mild form of sulfuric acid (p.554)
rain that is formed when sulphur dioxide combines with water vapour and falls to the earth
airborne pollutants such as sulphur dioxide dissolve in atmospheric water vapour to form an acid.
This should correctly be called acid precipitation because it includes rain, snow, sleet, fog and any other form of precipitation. It is produced as industrial byproducts in emissions of sulfur and nitrogen oxides from burning coal and petroleum products. Found throughout the world, its heaviest concentrations are in urban areas. Among other things, it harms aquatic wildlife, corrodes monuments and bridges, destroys exterior paint, kills forests, damages some agricultural soils, makes drinking water toxic by leaching lead from pipes, and reduces visibility.
The result of sulfur dioxide ( SO2) and nitrogen oxides ( NOx) reacting in the atmosphere with water and returning to earth as rain, fog, or snow. Broadly used to include both wet and dry deposition. The acid rain page provides a great deal of information about this issue.
The result of sulfur dioxide (SO2) and nitrogen oxides (NOx) reacting in the atmosphere with water and returning to earth as rain, fog, or snow. For more information, visit EPA's Acid Rain Web site.
rain that is made more acidic by sulfuric and/or nitric acid in the air, due to the burning of fossil fuels.
rain which has become acidic due to atmospheric pollution. The most important source of which is the burning of fossil fuels in motor vehicles and power stations
see also Pollution; Environmental Factors Adaptive Reuse: see Adaptive Use
Rain containing sulphuric acid and nitric acid.
precipitation (rain, snow, sleet etc) that is more acid than normal, generally due to human-produced air pollutants that dissolve in atmospheric moisture.
Caused by emissions from the burning of fossil fuels. When fuels such as coal, oil and natural gas are burned, many substances enter the atmosphere. Sulfur dioxide and nitrogen compounds, which contribute to air pollution, travel through the air and react with each other in sunlight to form secondary pollutants such as sulfuric acid and nitric acid. When rain contains these acids, it is called acid rain.
Rain made artificially acid by pollutants, particularly oxides of sulfur and nitrogen.
more properly called acid precipitation, it occurs when sulphur dioxide and nitrogen oxide emissions convert into such pollutants as sulphuric acid and nitric acid. Both dissolve easily in airborne water droplets.
rain that is especially acidic as the result of water vapor condensing onto particles of sulfate or nitrogen oxide.
When strong acids fall from the atmosphere in the form of rain, snow, fog or dry particles. The acid is the result of pollution caused mostly by sulphur oxides and nitrogen oxides that are discharged into the atmosphere by industry. It also is created by burning coal and oil, from the operation of smelting industries and from transportation. In the atmosphere, these gases combine with water vapour to form acids, which then fall back to Earth. The result often kills forests and sterilizes lakes.
The acidic rainfall which results when rain combines with sulfur oxides emissions from combustion of fossil fuels (coal).
formed when sulphur dioxide or other chemicals combine with water vapour causing the rain it forms to have lower the pH than normal
Rain which is slightly acidic due to the mixing in the atmosphere of various industrial atmospheric pollutants (e.g., sulphur dioxide) with naturally occurring oxygen and water vapour. Acid rain is thought to be partly responsible for the decline in freshwater fish populations and woodlands in parts of central and northern Europe.
Rain or other precipitation with a higher than normal acid range. Caused when polluted air mixes with cloud moisture. High acidity (low pH) can make lakes devoid of fish.
Cloud or rain droplets combine with gaseous pollutants, such as oxides of sulfur and nitrogen, to make falling rain or snow acidic.
Also called acid precipitation or acid deposition, acid rain is precipitation containing harmful amounts of nitric and sulfuric acids formed primarily by nitrogen oxides and sulfur oxides released into the atmosphere when fossil fuels are burned. It can be wet precipitation (rain, snow or fog) or dry precipitation (absorbed gaseous and particulate matter, aerosol particles or dust). Acid rain has a pH below 5.6. Normal rain has a pH of about 5.6, which is slightly acidic. The term pH is a measure of acidity or alkalinity and ranges from 0 to 14. A pH measurement of 7 is regarded as neutral. Measurements below 7 indicate increased acidity, while those above indicate increased alkalinity.
Rain mixed with sulfuric, nitric and other acids which arise from emissions released during the burning of fossil fuels.
Rain with a pH of less than 5.6; results from atmospheric moisture mixing with sulphur and nitrogen oxides emitted from burning fossil fuels or from volcanic activity.
Any rain, sleet, fog, dew, dust, or other precipitation with a pH less than clean rain (pH 5.6). Acid rain occurs when the by-products of combustion react chemically with air and water in the presence of sunlight to form mineral acids.
Rain with a harmful level of sulfuric, nitric and other acids. Proven deadly to some ecosystems, it arises from emissions released in burning of fossil fuels.
rain with a pH of less than 5.6; results from atmospheric moisture mixing with sulfur and nitrogen oxides emitted from burning fossil fuels; may cause damage to buildings, car finishes, crops, forests, and aquatic life.
Atmospheric precipitation with a pH below 3.6 to 5.7. Burning of fossil fuels for heat and power is the major factor in the generation of oxides of nitrogen and sulfur, which are converted into nitric and sulfuric acids washed down in the rain. See also atmospheric corrosion.
Rain which is especially acidic (pH5.2). Principal components of acid rain typically include nitric and sulfuric acid. These may be formed by the combination of nitrogen and sulfur oxides with water vapor in the atmosphere.
rainfall with a pH of less than 7.0. One source is the combining of rain and nitrogen and sulphur oxides, which are by-products of burning of fossil fuels in industry and in transportation. aerobic: requiring air or oxygen in order to exist (for an organism) or occur (for a process). aerosols: tiny solid or liquid particles suspended in the air. Aerosol particles play an important role in the climate system because they interact directly (through absorption and scattering) with radiation from the sun and the Earth, and influence cloud processes.
rain with a pH of less than 5.6 that has mixed with sulfur and nitrogen oxides in the atmosphere as a result of burning fossil fuel. Acid rain can damage buildings, wildlife and aquatic life.
Sulfur dioxide (SO2) and nitrogen oxides (NOx), along with other chemical compounds, are released during the combustion of fossil fuels. When these gases react in the atmosphere with water, oxygen, and other chemicals, they form acidic compounds. Sunlight increases the rate of most of these reactions. The resulting substances are wet (acid rain, snow, or fog) or dry (acidic gases or particulates) and may drift far from the original source before falling to the earth. The negative effects of these acidic deposits include damage to forests, soil, and aquatic ecosystems, damage to infrastructure and human health, and reduced visibility.
Rain, snow, hail, sleet, and fog polluted by chemicals in the air.
Precipitation that has a low pH. Acid rain is created when atmospheric water combines with sulfur dioxide and nitrous oxide emissions. These emissions are by-products of the combustion of fossil fuels. Acid rain can harm plant and animal life and alter soil conditions.
Also called acid precipitation or acid deposition, acid rain is precipitation containing harmful amounts of nitric and sulfuric acids formed primarily by nitrogen oxides and sulfur oxides released into the atmosphere when fossil fuels are burned. It can be wet precipitation (rain, snow, or fog) or dry precipitation (absorbed gaseous and particulate matter, aerosol particles or dust). The term pH is a measure of acidity or alkalinity and ranges from 0 to 14. A pH measurement of 7 is regarded as neutral. Measurements below 7 indicate increased acidity, while those above indicate increased alkalinity. Acid rain has a pH below 5.6. Normal rain has a pH of about 5.6, which is slightly acidic.
The precipitation of sulfuric acid and other acids as rain. The acids form when sulfur dioxide and nitrogen oxides released during the combustion of fossil fuels combine with water and oxygen in the atmosphere.
A term used to describe precipitation that has become acidic (low pH) due to the emission of sulfur oxides from fossil fuel burning power plants.
Rain that has become acidic due to the emission of sulfur dioxide and nitrogen oxides. To learn more, see the U.S. Environmental Protection Agency's Acid Rain Home Page.
Air pollution produced acid chemicals such as sulfur oxides and nitrogen oxides combine with moisture in the air and fall to the Earth as rain, snow, fog, or mist.
Acid rain is a generic term used for precipitation that contains an abnormally high concentration of sulfuric and nitric acid. These acids form in the atmosphere when industrial gas emissions combine with water, and have negative impacts on the environment and human health.
Rain water with a low pH (4.5 or lower) contaminated with pollutants in the air (sulfur dioxide, carbon dioxide and nitrous oxide).
Rain with a higher than normal acid range. Caused when polluted air mixes with cloud moisture. The "acid" in acid rain comes from sulfur oxides and nitrogen oxides, products of burning coal and other fuels and from certain industrial processes. Acid rain can make lakes devoid of fish and damage human health and property.
A mixture of rainfall and a small amount of nitric or sulfuric acid, created by contact with other gases.
forms of precipitation (such as rain, snow or sleet) containing high levels of sulphuric or nitric acids (with pH levels below 5.5-5.6). Also includes dry deposited gases and particles that fall back to earth from the atmosphere. According to the US EPA, approximately 2/3 of all SO2 and 1/4 of all NOx in the US come from electric power generation that burns fossil fuels such as coal. see also sulphur oxides and nitrogen oxides.
Acidic water usually pH 2.5 to 4.5, which poisons the ecosystem and adversely affects plants, fishes, and mammals. It is caused by industrial pollutants, mainly sulfur oxides and nitrogen oxides, emitted into the atmosphere and returning to earth in the form of acidic rain water.
Precipitation which has a pH of less than 5.6.
rain containing pollutants that give it a pH of less than 7.0.
Cloud droplets or raindrops combining with gaseous pollutants, such as oxides of sulfur or nitrogen, to make falling rain (or snow) acidic (pH less than 5.6). If fog droplets combine with such pollutants it becomes acid fog.
When rainfall occurs below the normal pH range, usually caused by contact of raindrops with atmospheric pollutants such as nitric & sulfuric oxides and carbon monoxide.
Occurs when sulphur dioxide and nitrogen oxide gases react in the atmosphere with water vapor to form acidic compounds. These gases can travel hundreds of kilometres before falling to the earth as rain, drizzle, snow or dry particles (this fallout is also known as “acid precipitation” or “acid deposition”).
Precipitation that becomes acidic due to air pollutants released into the atmosphere. The main sources of these pollutants are: coal-fired power plants, nickel and copper smelters, and motor vehicles. Soil, water, plants and building materials can be negatively affected. Walk, bike, carpool, or use transit to one of your regular destinations each week.
Airborne toxic contaminants, such as car emissions and the burning of other fossil fuels, enter the atmosphere and come back down to the land in the form of acid rain
Rain or snow contaminated by acids formed when air pollutants, especially sulphur dioxide (SO2) and nitrogen oxides (NOx), undergo chemical changes in the atmosphere.
Rain which is more acidic than pH 5.5.
Precipitation that has a low pH (less than pH 5.6, which is normal for "natural" precipitation); the precipitation becomes acidic when moisture in the air reacts with sulfur and nitrogen pollutants in the atmosphere; because of its low pH, acid rain has a harmful effect on some plants, soils and surface waters, buildings and, indirectly, on some organisms that live in surface waters.
falling rain (or snow) which has become acidic as a result of its combination with gaseous pollutants, such as oxides of sulfur and nitrogen
Rain that contains chemical pollutants and can harm living and nonliving things.
acid precipitation falling as rain.
Rainwater with a pH of less than 5.7 is acid rain. It is caused by the gases NO (from car exhaust fumes) and SO (from the burning of fossil fuels) dissolving in rain. Acid rain kills fish, kills trees, and destroys buildings and lakes.
moisture condensing and falling in drops which are mixed with air-born pollutants. The droplets have an acidic ph value.
Precipitation that carries to earth sulfuric and nitric acid accumulated from air pollutants.
rain that has become acidic (with a pH of less than 7) from mixing with sulfuric, nitric and other acids that are released into the atmosphere by the burning of fossil fuels.
precipitation that contains acidic components as a result of the burning of coal and other fossil fuels
Precipitation lower than the natural range of ~ 5.5. Acid rain occurs when sulfur dioxide (SO2) and nitrogen oxides (NOx) mix with the oxygen, water and other chemicals in the atmosphere to form different acidic compounds.
Cloud or rain droplets containing pollutants, such as oxides of sulfur and nitrogen, to make them acidic (e.g.. pH 5.6).
Rain that is more acidic than normal precipitation because water vapour has condensed on to particles of sulphate or nitrogen oxide.
A harmful type of precipitation that occurs when airborne chemicals like sulfur dioxide and nitrogen dioxide dissolve in rainwater.
rain that has absorbed acidic gases from the air. A form of air pollution, it can damage the environment as well as the health of humans and animals.
Acid rain is mainly caused by sulpher dioxide, nitrogen oxide and other pollutants when fossil fuels are burnt. Acid rain rarely falls near the source of the pollutant because smoke, fumes etc can be carried many miles by air currents. So the Scandinavia, for example, receives acid rain from British and German industry. The main effects of acid rain are on wildlife. Water in lakes also becomes very clear as fish and microscopic life are killed off. It is thought that acid rain is responsible for the death of some trees, specifically conifers, which gradually lose all their leaves and die.
Polluted air from factories and power stations often has sulphur dioxide in it. When this combines with rain water, you get acid rain. Acid rain damages plants and buildings, and can affect your health.
common name for any precipitation (rain, snow, sleet, hail, fog) having a high amount of sulfuric acid and/or nitric acid or having a pH lower than 5.6. Normal rain has a pH of 5.6 - 5.7. Accumulation of acids in lakes and rivers damages or kills plant and animal life. Acid rain also dissolves building materials and leaches nutrients out of soil resulting in crop damage. Fossil fuel power plants are a major source of acid rain.
Acid rain is polluted and harmful to the environment.
A combination of atmospheric moisture, airborne sulphur and nitrogen oxides to form sulphuric and nitric acids.
Atmospheric precipitation with a pH below 5.7. Acid rain is caused by oxides of nitrogen and sulphur released into the air through the burning of fossil fuels for human heat and power. These oxides are converted into nitric and sulphuric acids and washed down in the rain. Acid rain can be particularly damaging to stone buildings, outdoor metal and stone sculpture.
Rain containing relatively high concentrations of acid-forming chemicals that have been released into the atmosphere and combined with water vapor; harmful to the environment.
Acid rain is rain, snow or fog that is polluted by acid in the atmosphere and damages the environment.
a polluting rain formed from acids and acid forming compounds such as sulfur oxides from fossil fuels which react with water vapor in the environment to form sulfuric acid.
This is rain that has turned acidic as a result of the presence of sulfur or nitrogen oxides in the atmosphere. Acid rain can harm and even kill plants and aquatic life.
Precipitation having a low pH value caused by air polluted with sulfur dioxide, carbon dioxide or nitrous oxide.
Mildly acidic rain produced as a result of the release into the atmosphere of acidic gasses such as sulphur dioxide, generated by the combustion of fossil fuel in power stations and cars.
This is precipitation (rain, dew, etc) which has been become acidic due to airborne pollutants.
Air pollution produced when acid chemicals are incorporated into rain, snow, fog or mist. The "acid" in acid rain comes from sulfur oxides and nitrogen oxides, products of burning coal and other fuels and from certain industrial processes. The sulfur oxides and nitrogen oxides are related to two strong acids sulfuric acid and nitric acid. When sulfur dioxide and nitrogen oxides are released from power plants and other sources, winds blow them far from their source. If the acid chemicals in the air are blown into areas where the weather is wet, the acids can fall to Earth in the rain, snow, fog or mist. In areas where the weather is dry, the acid chemicals may become incorporated into dusts or smokes. Acid rain can damage the environment, human health and property.
industrial processes and fuel combustion (in vehicles, etc.) produce large quantities of CO2 ,SO2 and NO2 ; in the air these chemicals dissolve in water droplets to form acids; acid rain is harmful to the environment
rain of higher than normal acidity (pH less than 5) resulting from human-induced pollution effects, particularly sulphur dioxide and nitrogen oxides, in the atmosphere.
the precipitation of dilute solutions of strong mineral acids, formed by the mixing in the atmosphere of various industrial pollutants -- primarily sulfur dioxide and nitrogen oxides -- with naturally occurring oxygen and water vapor.
Precipitation which has been rendered (made) acidic by airborne pollutants.
Precipitation that is high in acid content as a result of pollution.
More properly Acid Precipitation, the acidity in rain and snow due to reaction with atmospheric gases from the burning of fossil fuels such as coal, oil, and gasoline.
Rain containing dissolved acidifying compounds, resulting from chemical pollution of the atmosphere by sulphur and nitrogen compounds. When deposited, these increase the acidity of the soil and water causing agricultural and ecological damage.
Occurs when sulfur dioxide and nitrogen oxide emissions are transformed in the atmosphere and return to the earth in rain, fog, or snow. Acid rain can damage lakes, forests, and buildings, contribute to reduced visibility, and may harm human health. Regulations have been implemented at the federal and state level to reduce acid rain. See also "Clean Air Act."
Acid rain (or more accurately acid precipitation)The term "acid rain" is commonly used to mean the deposition of acidic components in rain, snow, fog, dew, or dry particles. The more accurate term is "acid precipitation." http://pubs.usgs.gov/gip/acidrain/2.html (USGS) occurs when sulphur dioxide and nitrogen oxides are emitted into the atmosphere, undergo chemical transformations and are absorbed by water droplets in clouds. The droplets then fall to earth as rain, snow, mist, dry dust, hail, or sleet.