What portion of the volume of each atom or ion on the face of a unit cell is actually within the unit cell?
A) 3/4
B) 1/4
C) 1/2
D) all of it
E) none of it

Question

Quizplus · Accepted Answer

Each face of a unit cell contains half of each atom or ion inside it. Therefore, only half of the volume of each atom or ion on a face of a unit cell is actually within the unit cell. Since there are two faces per unit cell, the total volume of each atom or ion within the unit cell is equal to (2 faces)(1/2 volume per face) = 1 unit of volume. Thus, the portion of the volume of each atom or ion on the face of a unit cell that is actually within the unit cell is 1/2 or 50%.

What Portion of the Volume of Each Atom or Ion