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 Lead

Lead is a NATURALLY occurring bluish-gray metal found in small amounts in the earth’s crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source of exposure is OLD PAINT that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen. Several studies have looked for a link between exposure to lead in the WORKPLACE (mainly among battery workers and smelter workers) and lung cancer. Some of these studies have found a small increase in lung cancer risk. Studies have also looked at possible LINKS between workplace exposures to lead and other cancers, including cancers of the brain, kidney, bladder, colon, and rectum.

 Lead

Lead pollution primarily came from cars in the past. Today, lead pollution primarily comes from lead smelters, METAL processing plants and incinerators. Deposits of lead in soil can harm both humans and animals by ABSORBING it into a BODY.

 SULPHURIC acid

Acid rain is a formed due to the mixing of oxides of several harmful gases with the rain. Acid rain formation RESULT from both natural sources, such as VOLCANOES and decaying vegetation, and man-made sources, primarily emissions of sulfur dioxide and nitrogen oxides resulting from fossil fuel combustion. These gases react in the atmosphere with water, OXYGEN, and other CHEMICALS to form various acidic compounds. When this rain falls on the soil, the soil becomes acidic. Also, the leaves get destroyed and germinating seeds get corroded. Plants experience stunted growth. Thus, vegetation is destroyed. So, the correct answer is option D.

 The same ATOMIC NUMBER but DIFFERENT atomic MASSES

 The same ATOMIC NUMBER but different atomic masses

All ISOTOPES of the same ELEMENT have the same atomic number but different atomic masses.

 Plum and pudding

J.J. THOMSON’s proposed MODEL of ATOM is generally called plum and pudding model.

 Proton, neutron

The nucleus is the positively CHARGED CENTRE of an ATOM and CONTAINS most of its mass. It is COMPOSED of protons, which have a positive charge, and neutrons, which have no charge.

 ELECTRONS

Electrons are negatively CHARGED particles that generally ORBIT the nucleus of an atom. Electrons are much smaller than PROTONS or neutrons.

 Chromium, Copper and NICKEL

The metals COMMONLY used for ELECTROPLATING are Chromium, Copper and Nickel.

 Geothermal energy

Fossil fuels — coal, petroleum, and natural gas — are the primary culprit behind climate change. They CONTRIBUTE more than 80 percent of greenhouse gas emissions — and 98 percent of CO₂ emissions ALONE. On the contrary, Geothermal energy is thermal energy generated and STORED in the Earth. It is clean and sustainable.

 O₃ layer

Most commercial FLIGHTS are confined to the troposphere, but high-level supersonic AIRCRAFT inject pollutants into the stratosphere, which leads to the thinning of the ozone layer. Of these nitrogen oxides are ESPECIALLY harmful.

 Sulphur dioxide

Acid rain RESULTS when sulphur dioxide (SO2) and nitrogen oxides (NOX) are emitted into the atmosphere and transported by WIND and AIR currents.

 CFC

Ozone depletion OCCURS when CHLOROFLUOROCARBONS (CFCs) and halons—gases FORMERLY found in aerosol spray cans and refrigerants—are released into the ATMOSPHERE.

 SO₂

A flue-gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power PLANT’s steam-generating boiler, or other large combustion device. Flue gas is usually composed of carbon dioxide (CO2) and water VAPOR as WELL as nitrogen and excess oxygen remaining from the intake combustion air. It also contains a small percentage of pollutants such as particulate matter, carbon monoxide, nitrogen oxides and sulfur oxides. The flue gas stacks are often quite tall, up to 400 metres (1300 feet) or more, so as to disperse the EXHAUST pollutants over a greater area and thereby reduce the concentration of the pollutants to the LEVELS required by governmental environmental policy and environmental regulation.

 Depletion of fossil fuel reserves

The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects PLANTS and animals adversely. Acid rain CONTAINS H⁺, SO₄^2- ions which when added to the soil leaches the nutrients from the soil. Acid rain RENDERS the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of FRESH water affect the reproduction and survival or many species or fish.

 18

The M shell only holds eight electrons. The M shell can actually hold up to 18 electrons as you MOVE to higher atomic numbers. The MAXIMUM NUMBER of electrons you will FIND in any shell is 32.

 Chlorofluorocarbons

Ozone DEPLETION occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in AEROSOL spray CANS and refrigerants—are released into the atmosphere.

 OXIDES of N and S

Photochemical smog is CAUSED by oxides of SULPHUR and nitrogen.

 NO

Nitric OXIDE (NO) pollutant is the main PRODUCT of automobiles EXHAUST. NITROGEN dioxide (NO₂) pollutant is ALSO the product of automobiles exhaust.

 Different atomic NUMBER and different number of valence ELECTRONS

The atoms of different elements have different NUMBERS of electrons, protons, and neutrons. Every element is UNIQUE and has an atomic number. That number tells you the number of protons in every atom of the element. The atomic number is ALSO called the proton number.

 SULPHURIC ACID

Lead STORAGE BATTERY USES sulphuric acid.

 A, C and E

Recent research has shown that India’s groundwater faces the problem of presence of URANIUM, arsenic, and heavy metals in ground water USED for drinking. SORBITOL (used as artificial SWEETENER) and Formaldehyde (used in coating, etc) are not FAMOUS as water pollutants.

 PH meter

A pH meter is an electronic device USED for MEASURING the pH (acidity or alkalinity) of a liquid. A typical pH meter consists of a special measuring PROBE (a glass electrode) connected to an electronic meter that measures and displays the pH READING.

 CAUSTIC SODA

Sodium hydroxide is ALSO known as lye or soda , or caustic soda. At room temperature, sodium hydroxide is a WHITE crystalline odorless solid that absorbs moisture from the air.

 Calcium HYPOCHLORITE

Calcium hypochlorite is an inorganic COMPOUND with formula CaO(Cl)₂. It is the main active ingredient of COMMERCIAL products called bleaching powder, chlorine powder, or chlorinated lime, USED for water TREATMENT and as a bleaching agent.

 Textiles

Asbestosis, also called WHITE LUNG, lung disease that is CAUSED by the prolonged INHALATION of asbestos fibres.

 Hydrocarbon

The GASEOUS air pollutants of PRIMARY concern in urban settings include sulfur DIOXIDE, nitrogen dioxide, and carbon monoxide; these are emitted directly into the air from the combustion of fossil fuels.Smoke, a COLLECTION of airborne solid and liquid particulates and gases emitted when a material undergoes combustion, is also a pollutant. Hydrocarbon is an organic compound consisting ENTIRELY of hydrogen and carbon.

 Hydrogen

When hydrogen burns it BECOMES water VAPOR. There are no carbon or other COMPOUNDS released into the atmosphere. There are various compounds including carbon dioxide and carbon MONOXIDE released when other fuels are burnt.

 ARSENIC

Most POISONOUS POLLUTANT in WATER is arsenic.

 8

The ATOMIC NUMBER of OXYGEN is 8.

 10

10 ELECTRONS can be ACCOMMODATED in d-orbital.

 All of these

Silicon is used in Solar ENERGY devices, SEMICONDUCTORS and TRANSISTORS.

 CO

Carbon MONOXIDE is the main pollutant present in AUTOMOBILE EXHAUST.

 Less than 7

The PH LEVEL of lemon juice is, 2.00 to 2.60. It VARIES depending on the lemon. pH expresses DIFFERENT levels of acidity or alkalinity within a SOLUTION.

 Sullage

Sullage is all WASTEWATER generated in households or office buildings from streams without fecal CONTAMINATION, i.e. all streams except for the wastewater from toilets. Sources of sullage INCLUDE, e.g. sinks, showers, baths, clothes washing machines or dish washers.

 Battery

A Galvanic cell, also KNOWN as battery, is an electrochemical cell that derives electrical energy from SPONTANEOUS redox reactions taking place within the cell. It is TYPICALLY USED as a SOURCE of electrical power. By their nature, they produce direct current. A battery is a set of galvanic cells that are connected in parallel.

 Distillation

Alcohol can be separated from a MIXTURE of alcohol and water by FRACTIONAL distillation. This method works because the liquids in the mixture have DIFFERENT boiling points. When the mixture is heated, one liquid EVAPORATES before the other.

 Alizarin

Alizarin or 1,2-dihydroxyanthraquinone (also known as Mordant Red 11 and Turkey Red is an organic compound with formula C₁₄ H₈ O₄ that has been used throughout HISTORY as a prominent red DYE, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus. In 1869, it became the first natural pigment to be duplicated synthetically.Alizarin is the main ingredient for the MANUFACTURE of the madder lake pigments known to painters as Rose madder and Alizarin crimson. Alizarin in the most common usage of the term has a deep red colour, but the term is also part of the name for several RELATED non-red dyes, such as Alizarine Cyanine Green and Alizarine Brilliant BLUE.

 ZINC oxide

The compound zinc oxide (ZNO) is called PHILOSOPHER's wool. Alchemists, as part of their RITUALS, would burn zinc in air and collect the residue, which FORMED into white woolly tufts. They called it lana philosophica in Latin, meaning philosopher's wool.

 ANTOINE LAVOISIER

Antoine Lavoisier is KNOWN as the 'father of MODERN CHEMISTRY'.

 A combination of smoke and FOG

Smog is air pollution that reduces visibility. The term "smog" was first used in the EARLY 1900s to describe a mix of smoke and fog. The smoke usually came from burning coal. Smog was common in industrial AREAS, and remains a familiar sight in CITIES today. Today, most of the smog we SEE is photochemical smog.

 BAUXITE

Of all the ALUMINIUM ORES, bauxite is the CHIEF ORE of aluminium.

 N₂O

Nitrous OXIDE(N₂o) is a colourless, sweet-tasting GAS. It is ALSO known as "laughing gas".