Embibe Experts Solutions for Chapter: The p-Block Elements, Exercise 3: Exercise 3

Assertion : Boron forms only covalent compounds.
Reason : Due to small size of boron, the sum of its first three ionisation enthalpies very high.

Assertion: Most of the metal halides of group ${13}^{\text{th }}$ are dimerised through halogen bridging.
Reason : The metal species completes its octet by accepting electrons from halogen in those halogen bridged molecules.

Assertion : $\mathrm{Si}-\mathrm{Si}$ bonds are much weaker than $\mathrm{Si}-\mathrm{O}$ bonds.
Reason : Silicon forms double bonds with itself.

Assertion: Chlorine and sulphur dioxide both are bleaching agents.
Reason: The bleaching action of chlorine and sulphur dioxide is performed through the process of oxidation.

Assertion: Most of the reactions of fluorine are exothermic.
Reason: Fluorine atom is smaller and forms strong bonds with other elements and has low dissociation energy of the $\mathrm{F}-\mathrm{F}$ bond.

Asserion: Noble gases have very low boiling points.
Reason : Noble gases being monoatomic have no interatomic forces except weak dispersion forces.

Assertion: In a period noble gas has smallest atomic radius.
Reason: In case of noble gases atomic radii are taken as covalent radii.

Assertion : ${\mathrm{Pb}}^{4+}$ compounds are stronger oxidizing agents than ${\mathrm{Sn}}^{4+}$ compounds
Reason : The higher oxidation states for the group $14$ elements are more stable for the heavier members of the group due to "inert pair effect".