Niobium crystallizes in body-centred cubic structure. If the density is `8.55 g cm^(-3)`, calculate the atomic radius of niobium using its atomic mass `93 u`.

Explanation

To calculate the atomic radius of niobium (Nb) which crystallizes in a body-centered cubic (BCC) structure, we will follow these steps:

### Step 1: Determine the number of atoms per unit cell (Z)
In a body-centered cubic structure, there are:
- 1 atom at the center of the cube
- 8 corner atoms, each contributing \( \frac{1}{8} \) to the unit cell

Thus, the total number of atoms per unit cell (Z) is:
...