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- The troposphere is the first and lowest layer of the atmosphere of the Earth. - Gases mix at this layer. - Weather occurs here - Region where plants and animals breathe and live - Tropospheric pollution is caused due to the presence of unwanted gaseous or solid components in the air.

Mass of Solution = Mass of Solute + Mass of Solvent → 20g + 180g : Mass of Solution = 200g Mass Percent = \(\frac{Mass of Solute}{Mass of Solution} * 100%\) Mass percent = \(\frac{20}{200} * 100%\) Mass percent = 10%

The ideal metals to use for the task of recovering copper from an aqueous solution of copper sulphate are metals that are stronger reducing agents than copper but not reactive enough to react with the water that the solution consists of. Zinc, Aluminium, Iron are relatively inexpensive and being unreactive on exposure to water.

Reduction, any of a class of chemical reactions in which the number of electrons associated with an atom or a group of atoms is increased.

Redox (reduction/oxidation) describes all chemical reactions in which atoms have an increase or decrease in oxidation number (oxidation state).

In alcohols the hydrogen bond is formed due to the covalent bonds between one oxygen atom and one hydrogen atom in the hydroxyl group (O—H).

A coordinate covalent bond, also known as a dative bond, dipolar bond, or coordinate bond is a kind of two-center, two-electron covalent bond in which the two electrons derive from the same atom.

The hydrogen atom is the simplest of all atoms: it consists of a single proton and a single electron

An oxide is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula.

Acid rain results when sulfur dioxide (SO2) and nitrogen oxides (NOX) are emitted into the atmosphere and transported by wind and air currents. The SO2 and NOX react with water, oxygen and other chemicals to form sulfuric and nitric acids.

Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest halogen and is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour.

fluorine (F), most reactive chemical element and the lightest member of the halogen elements. As the most electronegative element, it is extremely reactive.

- Calcium trioxocarbonate (IV) occurs abundantly in earth's crust as limestone, chalk and marble - Eggshell is made almost entirely of calcium carbonate (CaCO3) crystals.

Aluminium sulfate is a salt soluble in water and is mainly used as a coagulating agent in the purification of drinking water. Copper demonstrated the greatest antimicrobial activity. The silver coatings demonstrated the second most antimicrobial surface.

metallurgy, art and science of extracting metals from their ores and modifying the metals for use.