what is the order of melting and boiling points of group 15 elements.explain it with reasoning
The melting point increases from N to As and then decreases from As to Bi in group 15.
The boiling point increases from N to Sb but Bi has low boiling point than Sb.
The melting and boiling points generally increase down a group due to increase in intermolecular forces with the increases in atomic size.
Sb and Bi show inert pair effect and form three covalent bonds instead of 5 due to which the interaction between their atoms is reduced resulting in decreased melting point. The size of Bi is big due to which decrease in interatomic interactions is still more due to which Bi has low melting point.
Bi has a lower boiling point than Sb because it has weak intermolecular forces of of attraction than Sb.
The boiling point increases from N to Sb but Bi has low boiling point than Sb.
The melting and boiling points generally increase down a group due to increase in intermolecular forces with the increases in atomic size.
Sb and Bi show inert pair effect and form three covalent bonds instead of 5 due to which the interaction between their atoms is reduced resulting in decreased melting point. The size of Bi is big due to which decrease in interatomic interactions is still more due to which Bi has low melting point.
Bi has a lower boiling point than Sb because it has weak intermolecular forces of of attraction than Sb.