Determine the Miller indices for the plane $\left( -a, 2b, \infty \right)$.

Assertion : Graphite is an example of a tetragonal crystal system.
Reason : For a tetragonal system,$a = b \neq c$,$\alpha = \beta = 90^o$,$\gamma = 120^o$.

Which of the following has a structure similar to a matchbox?

$SrO$ has a $NaCl$ structure. If the lattice constant $a = 0.514 \ nm$ and the ionic radius of $Sr^{2+} = 0.113 \ nm$,what is the radius of the $O^{2-}$ ion?

In a tetragonal crystal system,which of the following conditions is correct?

Which of the following crystal systems does not possess an axis of rotation?