The unit cell of copper corresponds to a face-centred cube of edge length 3.596 Å with one copper atom at each lattice point. The calculated density of copper in kg/m³ is-
[Molar mass of Cu : 63.54 g ; Avogadro Number = 6.022× 10²³]
1. 9076
2. 9100
3. 8994
4. 9087

An element with molar mass 2.7 × 10^–2 kg mol^–1 forms cubic unit cell with edge length 405 pm. If its density is 2.7 × 10³ kg m^–3 , the radius of the element in  × 10^–12 m is approximately- 

1. 148

2. 143

3. 140

4. 152

A diatomic molecule X₂ has a body-centred cubic (bcc) structure with a cell edge of 300 pm. The density of the molecule is 6.17 g cm^–3 . The number of molecules present in 200 g of X₂ is-
(Avogadro constant (N_A) = 6 × 10²³ mol^–1)
1. 8 N_A
2. 40 N_A
3. 4 N_A
4. 2 N_A

Percentages of free space in cubic close-packed structure and in body-centered packed structure are respectively-
1. 48% and 26%
2. 30% and 26%
3. 26% and 32%
4. 32% and 48%  

Experimentally it was found that a metal oxide has formula M_0.98O. Metal M, is present as M²⁺ and M³⁺ in its oxide. Fraction of the metal which exists as M³⁺ would be -

1. 6.05%

2. 5.08%

3. 7.01%

4. 4.08%