6.1 Diamond

1.1 Physical Properties
1.2 Chemical Properties

3.1 Borax
3.2 Orthoboric acid ($H_3BO_3$)
3.3 Diborane ($B_2H_6$)
3.4 Boron Halides $(BX_3)$

5.1 Physical Properties
5.2 Chemical Properties

6.1 Diamond
6.2 Graphite
6.3 Fullerene

7.1 Carbon Monoxide $(CO)$
7.2 Carbon Dioxide $(CO_2)$

8.1 Compounds of Silicon

9.1 Important compounds of Nitrogen

10.1 Nitrogen Oxide $N_2O$ or Laughing gas (Neutral)
10.2 Nitric Oxide $NO$ (Neutral)
10.3 Nitrogen trioxide $N_2O_3$
10.4 Nitrogen dioxide or Di-nitrogen tetroxide $NO_2$ or $N_2O$
10.5 Nitrogen pentaoxide $N_2O_5$

11.1 Nitric acid $HNO_3$
11.2 Oxidation of Metalloid and Inorganic compounds by Nitric acid
11.3 Action of Metals & Proteins

13.1 Ozone

14.1 Oxides of Sulphur
14.2 Oxyacids of Sulphur

It has a crystalline lattice. Each carbon atom is in $sp^3$ hybridised state and is tetrahedrally surrounded by other four carbon atoms at a distance of $154\ pm$.

The tetrehedra are lined together into a three dimensional giant molecule. The unit cell is cubic and held by strong covalent bonds.

It is very difficult to break extended covalent bonding and therefore, diamond is the hardest substance on the earth. In the rare modification of diamond, the tetrahedra are arranged differently to give a zinc blende like structure and a $F.C.C$ unit cell, per unit cell $8$ carbon atoms are present. (DIAGRAM)

It is used as an abrasive for sharpening hard tools, in making dies and in the manufacture of tungsten filaments for electric light bulbs.