Question

Diamond is hard because:

• A. all the four valence electrons are bonded to each carbon atoms by covalent bonds
• B. it is a giant molecule
• C. it is made up of carbon atoms
• D. it cannot be burnt

Answer 1

The correct option is A all the four valence electrons are bonded to each carbon atoms by covalent bonds

Diamonds are made from carbon that has been under extreme pressure and heat found in depths of 87 to 120 miles of the Earth’s mantle, where they are created in during a 1-3.3 billion-year time frame. The heat and pressure cause the diamonds molecules to change so that they’re so close together, the molecules can’t move (known as covalent bonding). The closeness of these molecules forms a rigid bond, therefore making the diamond-hard

Hence, the correct option is $A$.