The P-P-P bond angle in the tetra-atomic P4 molecule is 107 degrees - True or False?
What is the electronic configuration of Phosphorus?
It is [Ne]3s23p3Clearly there are 5 valence electrons. Do note that the 3p orbital is exactly half filed, as in it has 3 electrons in each of the three 3p orbitals, all with parallel spin!
How can the Phosphorus atom achieve its octet? Also, can the octet rule be extended? Octet can be achieved by forming three covalent bonds. For this to happen, the lone pair in the 3s orbital shall hybridize with the half-filled 3p orbital.
With the presence of vacant d orbitals - 3d0, Phosphorus can definitely extend its octet, much like in the case of the gas PCl5.
Each white Phosphorus atom forms 3 covalent bonds with 3 other Phosphorus atoms. Using VSEPR theory, we can surmise that the hybridization is sp3. With such a hybridization, the angle should theoretically be nearly 109 degrees. But look at the geometry of the molecule. What can you say about the bond lengths of all the bonds – are they all equal? Do note that the lone pairs are not shown. The shape of the molecule is pyramidal. Each P atom has a tetrahedral geometry (as per VSEPR theory).
In the tetra-atomic P4 molecule, the P-P-P angle is 60∘ (a regular tetrahedron with all edges equal in length).
Here each P-P-P angle is 60∘. Then, is our assumption of sp3 hybridization accurate? Theoretically if you are asked, do say sp3. But then the angle should not be as less as 60∘. Beyond the second period, or in other words – as we go down the group 15, the participation or intermingling of the s orbital in the sp3 hybrid orbital progressively decreases. Studies show that the possibility of fractional intermingling of orbitals is also there! This trend is attributed to the increasing size of the central atom as we go down the group.