To draw the Lewis dot structure for phosphorus tetrafluoride (PF4), we start by determining the total number of valence electrons. Phosphorus (P) has 5 valence electrons and each fluorine (F) has 7 valence electrons. Since there are four fluorine atoms, the total number of electrons is:
Valence Electrons:
- Phosphorus: 5
- Fluorine (4 atoms): 4 × 7 = 28
Total = 5 + 28 = 33 electrons
Next, we place phosphorus at the center and surround it with the four fluorine atoms. Each bond between phosphorus and fluorine uses 2 electrons, so we create four bonds (4 × 2 = 8 electrons used). This leaves us with:
33 – 8 = 25 electrons remaining.
Fluorine atoms already have 8 electrons in their outer shells due to the bonds, so we do not need to add lone pairs to them.
Now, we look at the molecular geometry of PF4. The molecule is tetrahedral since there are four bonding pairs of electrons around phosphorus with no lone pairs.
For the hybridization, we consider that phosphorus uses one 3s and three 3p orbitals to form four equivalent sp3 hybrid orbitals. This sp3 hybridization corresponds to the tetrahedral geometry.
In summary:
- Lewis Dot Structure: P is bonded to four F atoms with no lone pairs on P.
- Molecular Geometry: Tetrahedral
- Hybridization of Phosphorus: sp3