Chemical Bonding and Molecular Structure Test - 11

It follows that repulsion between two lone pairs is greater than repulsion between a lone pair and a bond pair, which in turn is greater than the repulsion between 
two bond pairs. Thus the presence of lone pairs on the central atom causes slight distortion of the bond angles from the ideal shape.

_SCl4 has 4 BP and 1 LP, and its shape is described as see-saw.

Antibonding molecular orbitals 

- have electron density which is not between the atoms (there is a node between the atoms) 

-are higher in energy than the original atomic orbitals 

-if these orbitals are occupied by electrons, it pulls the atoms away from each other and weakens or prevents bonding.

The molecules in which all the valence electrons are involved for single bond formation. Non-bonded lone pairs are absent. These molecules have less energy, hence are more stable

octet rule has following limitations i.e., 

1) formation of electron deficient atoms 

2) formation of super octet molecules 

3) inability to predict energy changes during bond formation 

4) this theory does not account for the shape of molecules