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Noble gases do not form molecules. In case of noble gases, the atomic radii corresponds to van der Waal’s radii. On the other hand, the atomic radii of other elements correspond to their covalent radii. By definition, van der Waal’s radii are larger than covalent radii. It is for this reason that noble gases are very large in size as compared to other atoms
belonging to the same period.

[Hint : (i) Due to their electron conflguration.
(ii) Due to its less solubility in blood.
(iii) Due to its high ionization enthalpy.]

[Hint : Because O₃ is endothermic compound/decomposition of O₃ is exothermic and ΔG is negative/decomposition of O₃ is spontaneous.]

(B)  3-chloro-3-ethylpentane

(E)  both SN1 and E1

Energy barrier : 

For the reacting species to make effetive collisions they should havesufficient energy to break the chemical bonds in the reacting molecules. The minimum amount of energy which the colliding moleccules must  possess is known as threshold energy. This means that only thosecollisions of reactants which possess energies greater than thresholdenergy will give products.

In the case of conformational isomerism, the energy barrier which prevents one conformer to convert into another by rotation, is called as orientation barrier. 

Kössel’s explanation of chemical bonding:

1. Noble gases separate the highly electronegative halogens and the highly electropositive alkali metals.
2. Halogens can form negatively charged ions by gaining an electron. Whereas alkali metals can form positively charged ions by losing an electron.
3. These negatively charged ions and positively charged ions have a noble gas configuration that is 8 electrons in the outermost shell. The general electronic configuration of noble gases (except helium) is given by ns2np6.
4. As unlike charges attract each other these unlike charged particle are held together by a strong force of electrostatic attraction existing between them. For example, MgCl2, the magnesium ion and chlorine ions are held together by force of electrostatic attraction. This kind of chemical bonding existing between two unlike charged particles is known as electrovalent bond.

(d) Cl₂ > Br₂ > I₂

Freudich adsorption isotherm is given by

\(\frac{x}{m}= kp^{1/n}\)

where n > 1

(i) Propene 

(ii) The absence of the plane of symmetry.

A catalytic process in which reactants and catalyst are in different phases are known as heterogenous catalysis. 

E.g: 

1. N₂(g) + 3H₂(g) \(\overset{Fe(s)}{\longrightarrow}\) 2NH₃

Here the reactants are gases, catalyst iron is a solid

2. Vegetable oil(l)  + H₂(g) \(\overset{Ni(s)}{\longrightarrow}\) Vanaspathi ghee

Here reactants and catalyst are in different phases.

A mixture of an alkyl halide and aryl halide gives an alkylarene when treated with sodium in dry ether and is called as wurtz – fitting reaction.

Entropy decreases OR ΔS = -ve

The average income is also called per capita income. 

Correct option is d. All of the above.

(c) Statement (I) is true but Statement (II) is false 

Antifreeze is mixed with coolant to avoid freezing of coolant in cold climate application of engine.

All engines whether gas, or liquid or coal or steam requires cooling.

Fission, Budding and Binary fission is asexual reproductions method. 

Filariasis is caused by worms Filarial worms.

People who get malaria are typically very sick with high fevers, shaking chills, and flue-like illness is called malarial fever.

Cause of Malaria: Malaria is caused by the bites from the female Anopheles mosquito which then infect the body with the parasite plasmodium. This is the only mosquito that can cause malaria.

Symptoms: Sensation of cold, shivering fever, headache and vomiting sweats followed by a return to normal temperature with tiredness deep breating and respiratory distress.

Prevention and control: Prevention and control measures involved the elimination of insect vector i.e. mosquito. Spray of DDT or thin films of oil in ditches helps in checking mosquito breeding. Treatment is through chloroquine and primaquine preparations.

• A transpiration driven ascent of xylem sap depends mainly on the following physical properties of water 
• Cohesion – mutual attraction between water molecule 
• Adhesion attraction of water molecules polar surfaces such as tracheary elements. 
• Surface tension -water molecules are attracted to each other in a liquid phase than in gas phase. 
• These properties gives water ability to rise in the thin tubes. 
• Water evaporates through stomata it results in pulling of water into leaf from the xylem transpiration can generate pull sufficient to lift a xylem sized column of water over 130 meters.

• It occur in yeast. 
• It involves anaerobic break down of glucose in absence of oxygen. 
• Enzyme pyruvic acid decarboxylase and alcohol dehydroginase catalyse reactions. 
• Carbon dioxide and ethanol are the end products.

1. Stroma 

2.

• Carboxylation 
• Carbon reduction
• Regeneration 

3. 

• 18 ATP 
• 12NADPH₂

Answer : (d) 3/4 

Explanation: After two half-lives 1/4th fraction of nuclei will remain undecayed . or 3/4th fraction will decay hence the probability that a nucleus decays in two half-lives is 3/4