Question

Which of the following statements concerning a metal crystallized in a face-centered cubic cell is/are CORRECT? 1. One metal atom is located on each face of the unit cell, where it is shared equally between four unit cells. 2. One metal atom is located at the center of the unit cell. 3. A metal atom is located at each of the eight lattice points, where it is shared equally between eight unit cells.

Answer 1

Answer:

Only 3 is correct.

Explanation:

The crystal of a metal or an ionic compound is called a cell, and there are 7 types of unit cells: cubic, tetragonal, orthorhombic, monoclinic, hexagonal, rhombohedral, and triclinic.

In a face-centered cubic cell (FCC) all angles are 90º and all lengths are equal. Each cubic cell has 8 atoms in each corner of the cube, and that atom is shared with 8 neighboring cells. So for a metal crystal, the atom is located at each of the eight lattice points, where it is shared equally between eight unit cells.