Assertion :- (A) Graphite is good conductor of electricity however diamond belongs to the category of insulators .
Rason (R ) Grapite is soft in anture on the hand diamond is very hard and brittle.

Options

A. If both assertion and reason and true and reason is the correct explanation of assertion.
B. If both assertion and reason and true and reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

B

Explanation

Diamond is bad conductor of electricity because all valence `e^(-)` of carbon are involved in bonding. In graphite however 3 out of 4 valence electrons are invovled in bonding, fourth electron remains free between adjacent layers which makes it a good conductor. Graphite is soft becaseu parallel layers are held together by week van der Waals force. However, diamond is hard due to compact three-diemensional network of bonding.