Most crystals show good cleavage because their atoms,ions or molecules are

For which of the following substances are the axial distances equal?

Chromium metal crystallises in a body-centred cubic $(bcc)$ lattice. The edge length of the unit cell is found to be $287 \, pm$. The atomic radius of chromium will be ............. $pm$.

The total number of Bravais lattice arrangements in different crystal systems is

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 :

How many space lattices are obtainable from the different crystal systems?