Calculate the fraction of empty space in cubic closest packing to five significant figures?

Answer 1

1. Find volume of spheres = 4/3pr3 and multiply by 4 since there are 4 spheres.

2. Find volume of units cell = l 3 = (2Ö2r)3.

3. Find volume of empty space = vol unit cell minus volume of spheres.

4. Divide volume empty space by volume of unit cell.

It works out to 25.952

Answer 2

In cubic closest packing, also known as face-centered cubic (fcc) structure, the fraction of empty space is approximately 26%. This means that about 26% of the total volume is empty space between closely packed spheres.