The second order Bragg diffraction of X-rays with λ = 1.00 Å from a set of parallel planes in a metal occurs at an angle $60°$. The distance between the scattering planes in the crystal is:

1.  2.00 Å
2.  1.00 Å
3.  0.57 Å
4.  1.15 Å

On the basis of unit cell concept a crystal has:

1. 7 systems
2. 14 systems
3. 230 systems
4. 32 systems

MgO and NaCl has similar structure. In MgO, magnesium is surrounded by how many oxygen atoms?
1. 2
2. 4
3. 6
4. 1

The cations and anions are arranged in an alternate form in:

1. Metallic crystal

2. Ionic crystal

3. Co-valent crystal

4. Semi-conductor crystal

A cube of a crystal has an A-atom placed at every corner and B-atom placed at every centre of face. The formula of the compound is:

1. AB

2. AB₃

3. A₂B₂

4. A₂B₃

The number of atoms per unit cell in a BCC structure is:

1. 9

2. 4

3. 2

4. 1