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 CHECKING the penetration of ULTRAVIOLET rays to the earth

Ozone in the stratosphere protects us from the Sun's harmful ultraviolet rays. However, ozone in the TROPOSPHERE, closer to Earth's surface, is a POLLUTANT and hazardous to our health.

 ALUMINIUM POWDER

In SILVERY PAINTS, the main CONSTITUENT is aluminium powder.

 GENUINE coins from COUNTERFEIT coins

The items AMENABLE to DETECTION by SOFT x-rays are genuine coins from counterfeit coins.

 SILVER Iodide

The most common CHEMICALS used for cloud seeding include silver iodide, potassium iodide and dry ice (solid carbon dioxide). Liquid PROPANE, which EXPANDS into a gas, has also been used.

 ADSORBENT

Charcoal is USED in WATER TREATMENT as adsorbent.

 Deposition of zinc on IRON

Galvanisation or galvanization (or galvanizing as it is most commonly called) is the PROCESS of applying a protective zinc coating to iron or steel, to prevent rusting. The most COMMON method is HOT dip galvanizing, in which steel sections are submerged in a bath of molten zinc.

 PSEUDOMONAS putida

The new STRAIN of BACTERIA produced by biotechnology in alcohol industry is Pseudomonas putida.

 Its aqueous solution turns red litmus blue

The main USE of litmus is to test whether a solution is ACIDIC or basic. For instance, ammonia GAS, which is ALKALINE, COLOURS the red litmus paper blue.

 Zone melting

When metals are required in a ultra pure state, the zone refining METHOD is USED. The principle-employed states that the impurities, which LOWER the melting point of a METAL remain preferentially dissolved in the liquid phase and purer metal will emerge in the solid phase.

 PROTON and Neutron

The nucleus is a collection of particles called PROTONS, which are positively charged, and neutrons, which are ELECTRICALLY NEUTRAL.

 Both A and R is TRUE and R is the CORRECT EXPLANATION of A

Both A and R is true and R is the correct explanation of A.

 Cat's-eye

A gemstone or gem (ALSO called a precious or semiprecious stone, a fine gem, or jewel) is a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments. However certain rocks (such as lapis lazuli) and organic materials (such as amber or jet) are not minerals, but are still used for jewelry, and are THEREFORE often considered to be GEMSTONES as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic VALUE. Topaz, Opal and Pearl are gemstones but Cat’s-eye is not a gem stone.

 Corrosion

Corrosion can be DEFINED as the DETERIORATION of MATERIALS by CHEMICAL PROCESSES.

 produce in SMALL amounts the hydrochloric ACID REQUIRED for the digestion of FOOD

The main use of SALT in the diet is to produce in small amounts the hydrochloric acid required for the digestion of food.

 NITROGEN

Below a height of about 86 kilometers, the three main gaseous elements, which together account for about 99.9% of the total atmosphere, EXIST in essentially constant proportion to the total: nitrogen COMPRISES 78% of air by volume, OXYGEN comprises 21% of air by volume, and argon comprises ANOTHER 0.9%.

 WASTE water released from kitchen

Sullage is domestic wastewater other than that which comes from the toilet. It results from food PREPARATION, PERSONAL WASHING, and washing of cooking and eating utensils and clothes. It is also called greywater (to distinguish it from blackwater which describes wastes containing human excrete).

 Both A and B

Mixture can be HOMOGENEOUS and HETEROGENEOUS.

 Bleaching powder

Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCL)₂. It is widely used for water TREATMENT and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochlorite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong SMELL of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is SAFER to handle.

 MERCURY VAPOUR and argon

Mercury vapour and argon are the most commonly USED substance in fluorescent TUBES.

 CARBON-14

Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (14C) to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants DIE or they are consumed by other organisms (for example, by humans or other ANIMALS), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the RADIOACTIVE decay of 14C.

 7

Periodic table CONTAINS 7 PERIODS.

 CARBON DIOXIDE

Carbon dioxide is a GREENHOUSE GAS.

 Can never be positive

The total energy of a revolving electron in any ORBIT is the sum of its kinetic and potential energies. Energy of an electron at INFINITE distance from the nucleus is ZERO. As an electron approaches the nucleus, the electron attraction INCREASES and the energy of electron decreases and THUS becomes negative. Thus, it can never be positive.

 6.02310²³

The VALUE of AVOGADRO NUMBER is 6.023 × 10²³.

 200

Maximum PERMISSIBLE CONCENTRATION of total HARDNESS in drinking WATER is 200.

 Compressed and hardened biomass

Coal is MOSTLY carbon with variable amounts of other elements; CHIEFLY HYDROGEN, sulphur, oxygen, and nitrogen. Coal is formed when dead plant matter decays into PEAT and is converted into coal by the heat and pressure of DEEP burial over millions of years.

 Fluorine

Fluorine is the most REACTIVE HALOGEN.

 0.5 mole

One mole of CO₂ has mass of 44 g and 32 g of O₂.
So 16 g of O₂ have 22 g of CO₂ or 0.5 MOLES of it.

 Sodium chloride

Antiseptics are ANTIMICROBIAL substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction. Antiseptics are generally distinguished from antibiotics by the latter’s ability to be transported through the lymphatic system to destroy bacteria within the body, and from DISINFECTANTS, which destroy microorganisms found on non-living objects. Some antiseptics are true germicides, capable of destroying MICROBES (BACTERIOCIDAL), while others are bacteriostatic and only prevent or inhibit their growth. Antibacterials are antiseptics that have the proven ability to act against bacteria. Microbicides which destroy virus particles are called viricides or antivirals. Sodium chloride,Used as a general cleanser. It is also used as an ANTISEPTIC mouthwash.

 ZINC SULPHATE

Zinc sulphate is not SOLUBLE in WATER.

 Mercury

Mercury has LEAST MELTING POINT.

 4

Covalency of an atom in a COVALENT COMPOUND is the number of covalent bonds FORMED by an atom. MAXIMUM covalency of Nitrogen is 4 (example - ammonium ions).

 CO and H₂

Water-gas A mixture of carbon monoxide (CO) and HYDROGEN (H2) produced by passing steam over red-hot COKE USING the ENDOTHERMIC reaction.

 CO₂

Aerated WATER is, CORRECTLY SPEAKING, water to which air is added. So aerated water is any water artificially impregnated with a large amount of gas (as CARBON dioxide). The term is, however, frequently applied to CARBONATED water.

 Neutron

Neutron has greatest MASS. Proton is a SUBATOMIC particle with SYMBOL p and positive electric CHARGE of +1 elementary charge and mass slightly LESS than that of neutron.

 Carbon dioxide

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.

 GERMAN SILVER

German Silver does not CONTAIN silver.

 FRANCIUM

The ELEMENT with the LOWEST ELECTRONEGATIVITY VALUE is francium, which has an electronegativity of 0.7.

 Lemon

Lemons, ORANGES, limes, and other citrus fruits naturally possess HIGH concentrations of CITRIC ACID. The juice of the lemon is about 5% to 6% citric acid, which gives lemons a sour taste. In fact, Citric acid was FIRST isolated in 1784 by the chemist Carl Wilhelm Scheele, who crystallized it from lemon juice.

 Cobalt

The STRUCTURE of B₁₂ is based on a corrin ring, which is similar to the porphyrin ring found in HEME, chlorophyll, and cytochrome. It contains the biochemically RARE element cobalt sitting in the CENTER of the ring. Also CALLED cobalamin, it is a water-soluble vitamin.

 Galvanization

Galvanization or galvanizing (also SPELLED galvanisation or galvanising) is the PROCESS of applying a protective zinc COATING to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the PARTS are submerged in a BATH of molten hot zinc.

 SO₂

SO₂ is SECONDARY AIR POLLUTANT.

 Renewable

The natural RESOURCES that GET replenished in nature are called as the renewable resources. These are the resources that can be used for UNLIMITED TIME span and can be replaced naturally such as sunlight, WATER, air etc.

 Softening

Softening is not INVOLVED in DRINKING WATER SUPPLY.

 Rain water

Rain water is CONSIDERED the purest form of water. Impurities and salts present in water on EARTH are LEFT behind during VAPORISATION by the sun.

 CALCIUM, Magnesium

Calcium and magnesium ion CAUSE HARDNESS of WATER.

 Hg

Hg is the CHEMICAL SYMBOL of MERCURY.

 Neon

Neon is a MONOATOMIC GAS AMONG the FOLLOWING.

 Nitrogen

There are a number of atmospheric gases which make up air. In the lower ATMOSPHERE or TROPOSPHERE, the MAIN gases are nitrogen and oxygen, which make up 78% and 21% of the VOLUME of air respectively. The REMAINING 1% of the atmospheric gases is made up of trace gases.

 METHYL ALCOHOL

Denatured alcohol is ethanol that has additives to make it undrinkable (poisonous), to discourage recreational CONSUMPTION. Different additives are used to make it difficult to use distillation or other simple processes to reverse the denaturation. METHANOL is commonly used both because its boiling POINT is close to that of ethanol and because it is toxic.