Determine the number of electron groups around the central atom for each molecule.
The number of electron groups around the central atom for each molecule.
All have 4 electron groups, all have sp3 hybrid orbitals, and tetrahedral ORBITAL geometry.
OF2: 2 bonded pairs, 2 unshared pairs. bent molecular geometry
NF3: 3 bonded pairs, 1 unshared pair. pyramidal molecular geometry
The best place to start when trying to figure out a molecule's geometry is its Lewis structure.
Carbon disulfide, CS2, will have a total of 16 valence electrons, 4 from the carbon atom and 6 from each of the two sulfur atoms.
The central carbon atom will form double bonds with the two sulfur atoms. These bonds will account for 8 of the 16 valence electrons of the molecule.
The remaining 8 valence electrons will be placed as lone pairs, two on each sulfur atom.
Now, molecular geometry is determined by the hybridization of the central atom. In this case, the carbon atom is surrounded by two regions of electron density, one for each double bond it forms with the sulfur atoms.
This means that its steric number will be equal to 2. The carbon atom will thus be sp hybridized. It will use one s and one p orbitals to form the hybrids, and the remaining p-orbitals to form pi bonds with the two sulfur atoms.
The molecular geometry will thus be linear, the basic AX2 model.
CH4: 4 bonded pairs. tetrahedral molecular geometry