(i) Zinc is placed above iron in the reactivity series. It has therefore reduced Fe²⁺
ions to Fe.
(ii) Zn(s) + Fe²⁺⟶Fe(s) + Zn²⁺(aq)
(iii) One should be very careful in selecting container for storing certain chemicals.

(i) According to Heisenberg, it is not possible to measure simultaneously the position and the momentum of a microscopic particle with absolute accuracy.
(ii) It has significance for microscopic particles. After his principle both wave and particle nature were considered and quantum mechanics was developed.
(iii) It has no impact on our daily life. It applies only to the moving microscopic particles which we cannot see with our eyes.

We know that monument like.Taj Mahal is being slowly disfigured and marble is getting discoloured. We can make people aware by passing this information. People living in city will be encouraged to use LPG in place of coal, kerosene or fire wood.

This can be done by using natural gas in place of fossil fuels which is a better fuel. Catalytic converters must be used in cars to reduce the effect of exhaust fumes in the atmosphere. We can make people aware by passing on this information.

A tight whirlpool of wind formed in the stratosphere which surrounds Antarctica is called polar vortex.

Methyl isocyanate.

DDT, BHC.

Pesticides are the substances used to kill unwanted pests.
For example, DDT.

Acids present in acid rain can react with marble (CaCO₃) and damage the monument.

Carbon monoxide (CO), sulphur dioxide (SO₂) and oxides of nitrogen (NO₂).

NO and CFCs

Stratosphere.

Primary pollutants are those which after their formation remains as it was before e.g., NO. Secondary pollutants are formed as a reaction with primary pollutants e.g., PAN (peroxyacyl nitrates).

(i) Tetrachloroethene, CI₂C = CCI₂ is suspected to be carcinogenic and also contaminates the ground water. This harmful effect will be prevented by using liquefied CO₂ along with suitable detergent
(ii) Use of liquefied CO₂ along with detergent will not be completely safe because most of the detergents are non-biodegradable and they cause water pollution. Moreover, liquefied CO₂ will ultimately enter into the atmosphere and contribute to the green house effect.

If domestic waste in a city is not properly managed, it may finds its way into sewers or may be eaten up by the cattle. The non-biodegradable waste like polythene bags, metal scrap etc., choke the sewers. The polythene bags if swallowed by the cattle can result into their death. Similarly, if industrial waste is not properly managed, it will cause pollution of the air, soil and water.