Distance between two octahedral void = a/{√2}here ...a is edge lengthin given question ....=> a/(√2) = 7.07=> a = 7.07×√2 = 9.998 ≈ 10 AngstromsDistance between two tetrahedral void = a/2Distance between two tetrahedral void = 10/2 = 5 Angstrom

Explanation:
FCC or Face-centered cubic arrangement is one of the most common arrangements of identical spheres in which spheres are placed at the corners of a cube and at the center of each face. The voids or spaces between spheres in a FCC arrangement can be classified into two types: octahedral voids and tetrahedral voids.

Octahedral Voids:
Octahedral voids are located at the center of each edge of the cube in a FCC arrangement. The distance between two nearest octahedral voids is equal to the edge length of the cube. In this case, the distance between two nearest octahedral voids is given as 7.07 angstrom.

Tetrahedral Voids:
Tetrahedral voids are located at the center of each face diagonal of the cube in a FCC arrangement. The distance between two nearest tetrahedral voids can be calculated using the following formula:

Distance between two nearest tetrahedral voids = edge length of the cube / sqrt(2)

Since the distance between two nearest octahedral voids is 7.07 angstrom, we can calculate the edge length of the cube as:

Edge length of the cube = 7.07 angstrom * sqrt(2)

Therefore, the distance between two nearest tetrahedral voids can be calculated as:

Distance between two nearest tetrahedral voids = (7.07 angstrom * sqrt(2)) / sqrt(2)

Distance between two nearest tetrahedral voids = 7.07 angstrom

Hence, the distance between two nearest tetrahedral voids in a FCC arrangement of identical spheres is 7.07 angstrom.

Summary:
- In a FCC arrangement of identical spheres, there are two types of voids: octahedral voids and tetrahedral voids.
- The distance between two nearest octahedral voids is equal to the edge length of the cube.
- The distance between two nearest tetrahedral voids is equal to the edge length of the cube divided by sqrt(2).
- Given the distance between two nearest octahedral voids as 7.07 angstrom, we can calculate the distance between two nearest tetrahedral voids as 7.07 angstrom.