Global Warming refers to average increase in the earth’s temperature due to increase in pollution which results in greenhouse effect which in turn leads to climate change. Global warming may lead to rise in the sea level due to melting of glaciers, shrinkage of forests, changes in the rainfall pattern and wide range of impacts on plants and humans. The greenhouse gases such as carbon dioxide accumulate into the atmosphere and trap heat that would normally exit into the outer space.

Hydrogen is not a greenhouse gas.

'Acid rain' is caused due to air pollution by Nitrous oxide and sulphur dioxide.

Ozone depletion occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere.

Over 500,000 people were exposed to methyl isocyanate (MIC) gas. The highly toxic substance made its way into and around the small towns located near the plant. Estimates vary on the death toll. The official immediate death toll was 2,259.

Tetra ethyl lead (C₂H₅)₄ Pb is used as an antiknock compound . It is mixed with petrol to improve its quality. Therefore automobile exhausts lead, which pollutes city.

The threshold limit value (TLV) of copper in atmospheric air is 1.0 mg/m³.

The correct sequence is China, USA, European Union, India.

Photochemical smog is a unique type of air pollution which is caused by reactions between sunlight and pollutants like hydrocarbons and nitrogen dioxide (NO and NO₂). Other components of the photochemical smog include Ozone (O₃) formaldehyde, peroxy benzoyl nitrate (PBzN), peroxy acetyl nitrate (PAN) and acrolein.

3 leak of toxic methyl isocyanate gas at a Union Carbide plant in the central Indian city of Bhopal produced history's worst industrial disaster, stunning India and the world.

Although the Germans were the first to use phosgene on the battlefield, it became the primary chemical weapon of the Allies. Phosgene was responsible for 85% of chemical-weapons fatalities during World War I. Mustard gas, a potent blistering agent, was dubbed King of the Battle Gases.

Sulphur dioxide level in the atmosphere can be reduced by using low sulphur fuels.

Photochemical smog which is mainly composed of ozone (O₃), Peroxyacetyl nitrate (PAN) and Nox, is also known as brown air where solar radiation is intense. In seasons of lesser solar radiation or areas, smog formation is incomplete and the air is referred to as grey air.

Main pollutants released from iron and steel industry are CO, CO₂ and SO₂.

A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth’s atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects. Greenhouse gases greatly affect the temperature of the Earth; without them, Earth’s surface would average about 33 degree C (91 degree F) colder than the present average of 14 degree C (57 degree F). Atmospheric concentrations of greenhouse gases are determined by the balance between sources (emissions of the gas from human activities and natural systems) and sinks (the removal of the gas from the atmosphere by conversion to a different chemical compound). The proportion of an emission remaining in the atmosphere after a specified time is the “Airborne fraction” (AF).

Biogas differs from natural gas in that it is a renewable energy source produced biologically through anaerobic digestion rather than a fossil fuel produced by geological processes. Biogas is primarily composed of methane gas, carbon dioxide, and trace amounts of nitrogen, hydrogen, and carbon monoxide.

LD stands for "Lethal Dose". LD50 is the amount of a material, given all at once, which causes the death of 50% (one half) of a group of test animals. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material.

A trickling filter, also known as percolating filter, is an artificial bed of stone or broken brick material over which waste water or sewage is allowed to sprinkle or to trickle. It is then collected through the under drainage system.

Lead is the most hazardous metal pollutants of automobile exhausts. Its effects are lead poisoning, anaemia, kidney disease, convulsions and also causes brain damage in children. It also affects central nervous system and distorts the red blood corpuscles.

CaSO₄.2H₂O (Gypsum) is added to cement clinker to retard setting action of cement.

Carbon monoxide is the major harmful gas emitted by the automobile vehicles which causes air pollution. Carbon monoxide (CO) - A product of incomplete combustion, carbon monoxide reduces the blood’s ability to carry oxygen; overexposure (carbon monoxide poisoning) may be fatal. Carbon Monoxide poisoning is a major killer. Carbon monoxide is a temporary atmospheric pollutant in some urban areas, chiefly from the exhaust of internal combustion engines (including vehicles, portable and back-up generators, lawn mowers, power washers, etc.), but also from incomplete combustion of various other fuels (including wood, coal, charcoal, oil, paraffin, propane, natural gas, and trash). Carbon monoxide is, along with aldehydes, part of the series of cycles of chemical reactions that form photochemical smog

An aerosol is a colloid of fine solid particles or liquid droplets, in air or another gas. The liquid or solid particles have diameter mostly smaller than 1 µm. They remain suspended in air for longer periods of time are transported to distances by winds. The finer particles could also be more easily re-suspended by subsequent wind action.

Main source of lead pollution is from leaded gasoline.

3 leak of toxic methyl isocyanate gas at a Union Carbide plant in the central Indian city of Bhopal produced history's worst industrial disaster, stunning India and the world.

All of the above are process of disposing of solid waste which cannot be reused or recycled.

Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, the remainder consisting of aluminium- and iron-containing clinker phases and other compounds. The ratio of CaO to SiO₂ shall not be less than 2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass. Cement sets when mixed with water by way of a complex series of chemical reactions still only partly understood. The different constituents slowly crystallise and the interlocking of their crystals gives cement its strength. Carbon dioxide is slowly absorbed to convert the portlandite (Ca(OH)₂) into insoluble calcium carbonate. After the initial setting, immersion in warm water will speed up setting. Gypsum is added as an inhibitor to prevent flash setting.

Asbestos is formed of Calcium and Magnesium.

Baeyer's reagent is an alkaline solution of cold potassium permanganate of violet colour solution. It is a strong oxidizing agent. As this solution interacts with a double bond compound the colour disappears and becomes colourless.

Stalactites and stalagmites are formed by water dripping or flowing from fractures on the ceiling of a cave. The dominant mineral in them is calcite (calcium carbonate) or CaCaO₃. Their largest displays are formed in caves of limestone and dolomite. Other minerals that may be deposited include other carbonates, opal, chalcedony, limonite, and some sulfides.

The atomic number of mercury is 80.

Quartz is a compound of one part silicon and two parts of oxygen, silicon dioxide, SiO₂. Quartz is the most abundant silica mineral. It is used in a number of industries, the important being glass, foundry, sodium silicate, silicon alloys, etc. The various grades of sodium silicate are characterized by their SiO₂:Na₂O weight ratio.

The most common heterocycles are those having five- or six-membered rings and containing heteroatoms of nitrogen (N), oxygen (O), or sulfur (S). The best known of the simple heterocyclic compounds are pyridine, pyrrole, furan, and thiophene.

Duma's method can be used to estimate nitrogen in all type of organic compounds. Detection of nitrogen is done by Lassigne's test. Estimation of phosphorus is done by Carius method.

Wood spirit is Methyl alcohol.

When formaldehyde and potassium hydroxide are heated, we get methyl alcohol and formic acid.

The new strain of bacteria produced by biotechnology in alcohol industry is Pseudomonas putida.

Mercury is emitted into air by burning garbage.

Rectified spirit, also known as ethyl alcohol of agricultural origin, is highly concentrated ethanol which has been purified by means of repeated distillation, called rectification. It typically contains 95% alcohol by volume.

Carbon Monoxide (CO) is one of the most harmful pollutants. Other gaseous air pollutants are carbon dioxide, oxides of sulfur, nitrogen, hydrocarbons, hydrogen sulphide, ozone and other oxidants. Particulate pollutants include mist, dust, smog, fumes etc.

3 leak of toxic methyl isocyanate gas at a Union Carbide plant in the central Indian city of Bhopal produced history's worst industrial disaster, stunning India and the world.

Nitrogen (N₂) is most stable at room temperature.

Bone ash is a white material produced by the calcination of bones. It is primarily composed of calcium phosphate. It is commonly used in fertilizers, polishing compounds and in making ceramics such as bone china. It also has historical uses in the manufacture of baking powders and assay cupels.

A pearl is a hard object produced within the soft tissue (specifically the mantle) of a living shelled mollusk. Just like the shell of a clam, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearls (baroque pearls) occur. The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries, and because of this, the word pearl has become a metaphor for something very rare, fine, admirable, and valuable.

Seventy percent of bone consists of hydroxyapatite, a calcium phosphate mineral (known as bone mineral). Tooth enamel is composed of almost ninety percent hydroxylapatite.

F₂ has a bond order of 2.5.

Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance.

Sodium chloride is the most common salt in sea water.

A growth fertilizer will have a high N content and relatively low P and K content. Ammonium nitrate is the highest Nitrogen fertilizer you can buy, and it is potent stuff. It is usually rated as 33-0-0 or 34-0-0. The bag contains 33% or 34% Nitrogen and the other 66% or 67% is inert material. Other formulations of growth fertilizers will contain 5, 6 or even 7 times more Nitrogen than anything else.