Assertion . Graphite is an example to hexogonal crystal system.
Reason . For a tetragonal system, ` a = b ne c, alpha = beta = 90^(@) , gamma = 120^(@)`

Options

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

Answer

D

Explanation

Correct A. Graphite is an example of hexagonal crystal system (Each C-atom is `sp^2`-hybridized and is linked to three other C-atoms in a hexagonal planar structure.
Correct R. For a tetragonal system, `a=b ne c, alpha = beta = gamma=90^@`. For a hexagonal system `a= b ne c, alpha = beta =90^@ , gamma =120^@`