Silicon covalent radius

Predict the molecular structures and bond lengths for SiF4, SiCh, SiBn, and SiL, assuming the covalent radius of silicon is 1.16 A. 

Hightened reactivity of functional groups (e.g. Cl, Br, OH, OR, OCOR, NH2, SH) at the atoms of silicon, aluminum, titanium, phoshorus and other elements in comparison with their reactivity binded with oxygen. This is due to the fact that the silicon atom is one and a half times bigger than the carbon atom it has a covalent radius of 0.117 nm, whereas the radius of the carbon atom is only 0.077 nm. It follows that functional groups of the Si atom are much more distanced from each other than... 

This is explained by the fact that a silicon atom is much larger (the covalence radius of a Si atom is 0.117 nm) than a carbon atom (the covalence radius of a C atom is 0.077 nm) therefore, the distances between the hydroxyl groups at the silicon atom are rather large and impair intramolecular condensation (such a reaction requires a considerable deformation of valence angles). 

The covalent radius of the silicon atom is one and one half that of the carbon atom thus rendering the silicon atom more sterically accessible. 

Boron forms perhaps the most extraordinary structures of all the elements. It has a high ionization energy and is a metalloid that forms covalent bonds, like its diagonal neighbor silicon. However, because it has only three electrons in its valence shell and has a small atomic radius, it tends to form compounds that have incomplete octets (Section 2.11) or are electron deficient (Section 3.8). These unusual bonding characteristics lead to the remarkable properties that have made boron an essential element of modern technology and, in particular, nan otechn ol ogy. 

---