Types of Unit Cell
Trending Questions
Name the parameters that characterize a unit cell.
- α=β=γ=90°
- α=β=γ≠90°
- α=γ=90° β≠90°
- α≠β≠γ≠90°
The number of atoms in face-centered cubic and hexagonal unit cells respectively are ?
4, 6
6, 4
2, 6
1, 6
- A4B
- AB4
- A8B
- AB8
- 8
- 4
- 6
- 2
- Spheres of the fourth layer are exactly aligned with those of the first layers arrangement,
- Second layer occupies 50% of the voids of first layer
- First layer is identical to the third layer
- Third layer is covering the octahedral voids of second layer
(Here, edge length of unit cell =l )
- l, √2 l, √3 l
- √3 l, √2 l, l
- l, √2 l, 2 l
- l, √2 l, l
Unit cell | Definition |
(a) Primitive | (i) Contains one constituent at its body-centre other than corners |
(b) End-centred | (ii) constituents only at the corners |
(c) Face-centred | (iii) constituents at the centre of any two opposite faces other than corners |
(d) Body- centred | (iv) constitutents at the centre of each face other than corners |
(v) constitutents only at the centre of cell |
- (a)-(ii), (b)-(v), (c)-(iv), (d)-(i)
- (a)-(v), (b)-(ii), (c)-(iv), (d)-(i)
- (a)-(ii), (b)-(iii), (c)-(iv), (d)-(v)
- (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)
- cubic
- hexagonal
- orthorhombic
- rhomobohedral
and crystallize in Bcc and Fcc type of crystals respectively. What will be the number of atoms of and present in the unit cell of their Respective crystal
- Six octahedral voids and eight tetrahedral voids
- Eight octahedral voids and six tetrahedral voids
- Six octahedral voids and six tetrahedral voids
- Eight octahedral voids and four tetrahedral voids.
- 288.38 pm
- 1538.06 pm
- 769.03 pm
- 144.19 pm
The volume of the HCP unit cell is
24√2 r3
16√2 r3
12√2 r3
643√3 r3
- 8
- 6
- 1
- 0
- 4 and 2
- 9 and 14
- 14 and 9
- 2 and 4
A solid has a structure in which W atoms are located at the corners of a cubic lattice, O atoms at the centres of edges and Na atom at the centre of the cube. The formula of the compound is
NaWO2
NaWO3
Na2WO3
NaWO4
Given: 1 amu=1.66×10−24 g
- 0.214×10−8 cm
- 2.512×10−8 cm
- 1.414×10−8 cm
- 3.6×10−8 cm
- 2√2a
- √2a
- a√2
- 2a
The atoms not touching each other are (Atoms
numberd 3 is face centre of front face)
- 3 and 4
- 1 and 3
- 1 and 2
- 2 and 4
- A2B2
- AB
- A2B3
- AB3
The volume of the HCP unit cell is
24√2 r3
16√2 r3
12√2 r3
643√3 r3
NH4Cl crystallizes in a body-centered cubic lattice with an edge length of unit cell equal to 387 pm. If the radius of the Cl− ion is 181 pm, the radius for NH+4 ion is?
154.1 pm
92.6 pm
366.3 pm
None of these
- 1
- 4
- 2
- Cubic close packing gives fcc structure
- Fourth layer is identical to the first layer
- Cubic close packing gives bcc structure
- Fourth layer is identical to the second layer