Question

Why carbon does not make tetra bond with another carbon atom

Answer 1

Carbon can only form tetra bonds with itself if it is sp3 hybridized and when its is sp3 hybridized then it has a tetrahedral structure with the four bonds pointing to the the corners of the regular tetrahedron.But if the two central carbon atom is sp2 or sp hybridized then it cannot form tetra sigma bonds with itself since one bond will be pi bond.And other then that carbon also forms three bonds in graphite with the fourth bond very weak.But if you consider both sigma and pi bond then carbon does form tetra bonds in all the organic compounds but in some cases such as carbene it forms only two bonds and in many inorganic compounds too