Respuesta :
Explanation:
Metallic solids are defined as the solids in which atoms of metals are held together by metallic bonds. These bonds are much stronger than an ionic bond.
In metallic solids, the electrons are delocalized in nature. On the other hand, ionic solids have strong bonds due to the presence of opposite charges on its combining atoms.
Molecular solids are defined as the solids in which atoms are combined together through Vander waal forces. Hence, molecular solids have low boiling point.
(a) It is known that [tex]N_{2}[/tex] is a molecular solid, NaF is an ionic solid, in [tex]NH_{3}[/tex] there exists hydrogen bonding between the molecules, and Ni is a metallic solid. Hence, the given materials are placed according to highest B.P. to lowest B.P. as follows.
Ni > NaF > [tex]NH_{3}[/tex] > HI > [tex]N_{2}[/tex]
(b) Ag is a metallic solid, and KCl is an ionic solid. Oxygen atom is more electronegative than bromine atom. So, the boiling point of [tex]H_{2}O[/tex] is more than the boiling point of HBr. Whereas Ar is a noble gas and it has low boiling point.
Hence, the given materials are placed according to highest B.P. to lowest B.P. as follows.
Ag > KCl > [tex]H_{2}O[/tex] > HBr > Ar
(c) Fe is also a metallic solid and electronegativity of fluorine is more than the electronegativity of chlorine. Hence, HF has high boiling point than HCl. And, [tex]F_{2}[/tex] being a covalent compound has weak intermolecular forces. So, the boiling point of [tex]F_{2}[/tex] will be the least.
Therefore, the given materials are placed from highest B.P. to lowest B.P. as follows.
Fe > LiF > HF > HCl > [tex]F_{2}[/tex]
