carbon compounds usually have weak force b/w the atoms but  diamond is considered as the hardest substance on earth even though it is a carbon compound?why?

Hi Sagarchetipally07,

In diamonds, each carbon atom is bonded to four different carbon atoms, giving rise to a tetrahedral structure. These small tetrahedrons combine to form a rigid 3D structure in which each carbon atom is bonded to four other carbon atoms.

 

 

 

 

It is because of this 3D structure that a diamond is so hard. Infact, it is the hardest substance known.

Hope, this clears your doubt.

Cheers!