White phosphour is a soft and low melting substance while red phosphorus is a hard and high melting substance - explain.

Explanation

White phosphorus is tetra - atomic `(P_(4))` in which four P atoms are located at the four corners of a regular tetrahedron . Its surface area is very samll for which the van der Waals force of attraction becomes very low which makes it solft and low melting . In red phosphorus , a large number of `P_(4)` tetrahedrons, by cleavage on inner P- P bonds, form P - P bonds among themselves to give a polymeric structure. Thus the van der Waals to give a polymeric structure. Thus the van der Waals force of attraction becomes high melting substance .