Maximum possible number of three-dimensional and two-dimensional lattices are respectively:

When atoms are placed at the corners of all $12$ edges of a unit cell,what is the number of atoms present per unit cell?

The parameters of the unit cell of a substance are $a=2.5, b=3.0, c=4.0, \alpha=90^{\circ}, \beta=120^{\circ}, \gamma=90^{\circ}$. The crystal system of the substance is :

The parameters $a = b = c$ and $\alpha = \beta = \gamma \neq 90^\circ$ belong to which crystal system?

Distinguish between
$(i)$ Hexagonal and monoclinic unit cells
$(ii)$ Face-centred and end-centred unit cells.

Which type of unit cell from the following is common to all seven types of crystal systems?