Valence-shell electron-pair repulsion theory geometry, central atom

VSEPR theory The VSEPR (valence shell electron-pair repulsion) theory says that the electron pairs around a central atom will try to get as far as possible from each other in order to minimize the repulsive forces. This theory is used to predict molecular geometry. 

The valence shell electron pair repulsion theory states that electron pairs aroimd the central atom of the molecule arrange themselves to minimize electronic repulsion the electrons orient themselves as far as possible from each other. Two electron pairs around the central atom lead to a linear arrangement of the attached atoms three indicate a trigonal planar arrangement, and four result in a tetrahedral geometry. Both lone pair and bonding pair electrons must be taken into accoimt when predicting structure. Molecules with fewer than four and as many as five or six electron pairs around the central atom also exist. They are exceptions to the octet rule. 

Valence shell electron pair repulsion theory (VSEPR) can be used to predict the shapes of molecules. According to this theory, the geometry of a molecule is such that the valence-electron pairs of the central atom are kept farthest apart to minimize the electron repulsions. Again, you have to view molecules in terms of Lewis structure so that the shape of the molecules can be predicted with the VSEPR theory. 

VALENCE SHELL ELECTRON PAIR REPULSION THEORY Table 8-1 Electronic Geometry versus Number ot Electron Groups (eg) on Central Atom... 

The hybridized orbital approach is a simplified way of predicting the geometry of a molecule with three or more atoms by mixing the valence orbitals of its central atom. An alternative approach, valence shell electron-pair repulsion (VSEPR) theory, accomplishes the same thing in a more qualitative way. 

VSEPR stands for valence shell electron pair repulsion. VSEPR theory can be used to predict actual geometries of molecules and composite ions. To be more precise it is a matter of determining bond directions and angles from the central atom in a molecule or composite ion to the other atoms. VSEPR theory can very shortly be formulated as follows ... 

Lewis theory, in combination with valence shell electron pair repulsion (VSEPR) theory, can be used to predict the shapes of molecules. VSEPR theory is based on the idea that electron groups—lone pairs, single bonds, or multiple bonds—repel each other. This repulsion between the negative charges of electron groups on the central atom determines the geometry of the molecule. For example, consider CO2, which has the Lewis structure ... 

We can predict the geometry of simple molecules using valence-shell electron-pair repulsion (VSEPR) theory. This theory is based on the idea that bonded and nonbonded electron pairs around a central atom repel one another. Hence, they are arranged in a geometry that provides maximum separation in space, and therefore rninimum electron repulsion. For bonds to carbon, the following rules apply ... 

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