Q: Which of the following metal(s) show(s) hexagonal close packed structure (hcp) and which show face centred cubic (fcc) structure?

Explanation:

Hexagonal close-packed (hcp) and face-centered cubic (fcc)

Hexagonal close-packed (hcp) and face-centered cubic (fcc) are two types of crystal structures found in metals. Understanding which metals adopt these structures helps in determining their physical properties such as strength, ductility, and melting points.

In the given options:

– Magnesium (Mg) and Zinc (Zn) both crystallize in the hcp structure. The hcp arrangement allows these metals to have a high packing efficiency with atoms arranged in a hexagonal pattern, which contributes to their specific mechanical properties.

– Silver (Ag) and Copper (Cu) crystallize in the fcc structure. The fcc structure is characterized by atoms positioned at each of the corners and the centers of all the cube faces of the unit cell. This arrangement provides high ductility and malleability, which is why metals like silver and copper are easily shaped and formed.

Therefore, Option B, which lists Mg, Zn, Ag, and Cu, correctly identifies that Magnesium and Zinc have a hexagonal close-packed structure, while Silver and Copper have a face-centered cubic structure.