If 'a’ stands for the edge length of the cubic systems: simple cubic, body-centered cubic, and face-centered cubic, then the ratio of radii of the spheres in these systems will be respectively:

1. $\frac{1}{2}\mathrm{a :}$ $\frac{\sqrt{3}}{4}\mathrm{a}$ $:$ $\frac{1}{2\sqrt{2}}\mathrm{a}$

2. $\frac{1}{2}\mathrm{a :}$ $\sqrt{3}\mathrm{a}$ $:$ $\frac{1}{\sqrt{2}}\mathrm{a}$

3. $\frac{1}{2}\mathrm{a :}$ $\frac{\sqrt{3}}{2}\mathrm{a}$ $:$ $\frac{\sqrt{2}}{2}\mathrm{a}$

4. $1\mathrm{a :}$ $\sqrt{3}\mathrm{a}$ $:$ $\sqrt{2}\mathrm{a}$

Subtopic:  Voids, Radius Ratio & Coordination Number |
86%
From NCERT
AIPMT - 2008
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In a cubic unit cell, atom A is present at each corner, atom B at each face centre and atom C at the body centre. The simplest formula of the solid is :

1. ${\mathrm{AB}}_{2}\mathrm{C}$

2. ${\mathrm{A}}_{2}\mathrm{BC}$

3. ${\mathrm{AB}}_{3}\mathrm{C}$

4. ${\mathrm{ABC}}_{3}$

Subtopic:  Voids, Radius Ratio & Coordination Number |
85%
From NCERT
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An ionic compound has a unit cell consisting of A ions at the corners of a cube and B ions on the centers of the faces of the cube. The empirical formula for this compound would be :

1. AB

2. A2B

3. AB3

4. A3B

Subtopic:  Voids, Radius Ratio & Coordination Number |
84%
From NCERT
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The total number of tetrahedral voids in the face centered unit cell is -

1. 6

2. 8

3. 10

4. 12

Subtopic:  Voids, Radius Ratio & Coordination Number |
82%
From NCERT
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The edge lengths of the unit cells in terms of the radius of spheres constituting fcc, bcc, and simple cubic unit cells are respectively -

1.

2.

3.

4.

Subtopic:  Voids, Radius Ratio & Coordination Number |
81%
From NCERT
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If Xenon crystallizes in face center cubic lattice and the edge of the unit cell is 620 pm, then the radius of the Xenon atom is-

1. 219.20 pm

2. 438.5 pm

3. 265.5 pm

4. 536.94 pm

Subtopic:  Voids, Radius Ratio & Coordination Number |
79%
From NCERT
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In a face centred cubic lattice, atom A occupies the corner positions and atom B occupies the face centre positions. If one atom of B is missing from one of the face centred points, the formula of the compound is -

1. AB2

2. A2B3

3. A2B5

4. A2B

Subtopic:  Voids, Radius Ratio & Coordination Number |
78%
From NCERT
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Copper crystallizes in a face-centered cubic lattice with a unit cell length of 361 pm. The radius of the copper atom is:

1. 128 pm

2. 157 pm

3. 181 pm

4. 108 pm

Subtopic:  Voids, Radius Ratio & Coordination Number |
78%
From NCERT
AIPMT - 2009
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Same coordination number for cations and anions is present in:

 1 Cl- ions form Fcc lattice and Na+ ions occupy all octahedral voids of the unit cell. 2 Ca2+ ions form Fcc lattice and F- ions occupy all the eight tetrahedral voids of the unit cell. 3 O2- ions form Fcc lattice and Na+ ions occupy all the eight tetrahedral voids of the unit cell. 4 S2- ions form Fcc lattice and K+ ions go into alternate tetrahedral voids of the unit cell.
Subtopic:  Voids, Radius Ratio & Coordination Number |
78%
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An element crystallizes in a structure having FCC unit cell of an edge length 200 pm. If 200 g of this element contains 24 x 1023 atoms, the density of the element is -

1. 50.3 g/cc

2. 63.4 g/cc

3. 41.6 g/cc

4. 34.8 g/cc

Subtopic:  Voids, Radius Ratio & Coordination Number | Density & Packing Fraction |
75%
From NCERT
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