Explain VSEPR theory . Applying this theory to predict the shapes of `IF_(7)`, and `SF_(6)`.

Explanation

Important principles of VSEPR Theory are as follows :
The shape of the molecules depends on the number of valence shell electron pair around the central atom.
There are two types of electron pairs namely bond pairs and lone pairs. The bond pair of electrons are those shared between two atoms, while the lone pairs are the valence electron pairs that are not involved in bonding .
Each pair of valence electrons around the central atom repels each other and hence, they are located as far away as possible in three dimensional space to minimize the repulsion between them.
The repulsive interaction between the different types of electron pairs is in the following order .
`lp - lp gt lp - bp gt bp - bp`
lp - lone pair , bp - bond pair
`IF_(7)` : The hybridisation of `IF_(7)` is `SP^(3) d^(3)` and its shape is pentagonal bi pyramidal

`SF_(6)` : The molecule `SF_(6)` belongs of `AB_(6)` type consisting of `6BP` of electrons around the central sulphur atoms. The geometrical arrangement will be a regular octahedral .