Crystal Lattices and Unit Cells — Prelims Questions

Which of the following unit cell parameters correctly describes a rhombohedral (trigonal) crystal system?

A compound forms a Face-Centered Cubic (FCC) lattice. If atoms of element X are at the corners and atoms of element Y are at the face centers of the unit cell, what is the formula of the compound?

How many Bravais lattices are associated with the cubic crystal system?

If a unit cell has axial lengths $a \ne b \ne c$ and interfacial angles $\alpha = \gamma = 90^\circ, \beta \ne 90^\circ$, what is the crystal system?

In a body-centered cubic (BCC) unit cell, what is the effective number of atoms (Z)?

In a crystalline solid, if the constituent particles are located only at the corners of the unit cell, what type of unit cell is it?