Which of the following pairs of compounds is isomorphous?

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?

In a face-centred cubic $(FCC)$ unit cell,the edge length $(a)$ in terms of atomic radius $(r)$ is:

Which of the following crystals has a unit cell such that $a \neq b \neq c$ and $\alpha \neq \beta \neq \gamma \neq 90^{\circ}$?

Number of crystal systems from the following where body-centered unit cell can be found,is $.........$ Cubic,tetragonal,orthorhombic,hexagonal,rhombohedral,monoclinic,triclinic.

Which of the following is correct regarding crystal systems?