Question

why diamond is very hard and rigid​

Answer 1

Answer:

The heat and pressure causes the diamonds molecules to change so that they're so close together, the molecules cannot move. The closeness of these molecules form a rigid bond, therefore making the diamond hard.

Answer 2

• Diamond made up of carbon atoms.
• The outermost shell of each carbon atom has four electrons.
• In diamond, these electrons are shared with four other carbon atoms to form very strong chemical bonds resulting in an extremely rigid tetrahedral crystal.
• It is this simple, tightly-bonded arrangement that makes diamond one of the hardest substances on Earth.

i hope it helps you.