From the fact that the length of the side of a unit cell of lithium is 351 pm. Calculate its

atomic radius. Lithium forms body-centered cubic crystals.

Atomic radius of silver is 144.5 pm. The unit cell of silver is a face centred cube. Calculate the density of silver.

A metallic elements exists as a cubic lattice. Each edge of the unit cell is 2.88Å. The density of the metal is 7.20 g cm^–3.Number of unit cells will be present in 100 gm of the metal is: 

Silver crystallizes in a face centred cubic system, 0.408 nm along each edge. The density of silver is 10.6 $g/c{m}^3$ and the atomic mass is 107.9 g/mol. Calculate Avogadro's number.

Fraction of total volume occupied by atoms in a simple cube is

A solid AB has the NaCl structure. If radius of cation A⁺ is 120 pm, calculate the maximum possible value of the radius of the anion B^–

The first order reflection (n = 1) from a crystal of the X-ray from a copper anode tube $(\lambda =0.154nm)$ occurs at an angle of 16.3°. What is the distance between the set of planes causing the diffraction.

The diffraction of barium with X-radiation of wavelength 2.29Å gives a first – order reflection at 30°. What is the distance between the diffracted planes.

When an electron in an excited Mo atom falls from L to the K shell, an X-ray is emitted. These X-rays are diffracted at angle of $7{.75}^o$ by planes with a separation of 2.64Å. What is the difference in energy between K-shell and L-shell in Mo assuming a first-order diffraction. $(\sin 7{.75}^o=0.1349)$

Which is the incorrect statement?

In calcium fluoride, having the fluorite structure, the coordination numbers for calcium ion (Ca²⁺) and fluoride ion (F^-) are

Lithium has a bcc structure. Its density is 530 kg m^-3 and its atomic mass is 6.94 gmol^-1.

The edge length of a unit cell of lithium metal is -

(N_A=6.02 x10²³ mol^-1)

The ionic radii of A⁺ and B^- ions are 0.98 x 10^-10 m and 1.81 x10^-10 m.  The coordination

number of each ion in AB is.

The correct statement regarding defects in the crystalline solid is

The vacant space in bcc lattice cell is ;

if a is the length of the side of a cube, the distance between the body centered atom and

one corner atom in the cube will be :-

Copper crystallises in a face-centred cubic lattice with a unit cell length of 361 pm. What

is the radius of copper atom in pm?

Lithium metal crystallises in a body centred cubic crystal. If the length of the side of the

unit cell of lithium is 351 pm, the atomic radius of the lithium will be

The incorrect statement among the following is -

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,

$$\begin{gathered} \left(\mathrm{a}\right) \frac{1}{2}\mathrm{a}: \frac{\sqrt{3}}{4}\mathrm{a}:\frac{1}{2\sqrt{2}}\mathrm{a} \left(\mathrm{b}\right) \frac{1}{2}\mathrm{a}:\sqrt{3}\mathrm{a}:\frac{1}{\sqrt{2}}\mathrm{a} \\ \left(\mathrm{c}\right) \frac{1}{2}\mathrm{a}:\frac{\sqrt{3}}{2}\mathrm{a}:\frac{\sqrt{2}}{2}\mathrm{a} \left(\mathrm{d}\right) 1\mathrm{a}:\sqrt{3}\mathrm{a}:\sqrt{2}\mathrm{a} \end{gathered}$$

Percentage of free space in a body centered cubic unit cell is

With which one of the following elements silicon should be doped so as to give p-type of semiconductor?

The fraction of total volume occupied  by the atoms present in a simple cube is:

$$\begin{gathered} 1. \mathrm{\pi }/6 \\ 2. \mathrm{\pi }/3\sqrt{2} \\ 3. \mathrm{\pi }/4\sqrt{2} \\ 4. \mathrm{\pi }/4 \end{gathered}$$

A compound forms hcp structure. The total number of voids in 0.5 mol will be- 

Iron has a body centred cubic unit cell with the cell dimension of 286.65 pm. Density of iron is 7.87 g cm^-3. The value of  Avogadro's number based on this data will be -

(Atomic mass of Fe = 56.0 u)

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

3.  133 $\mathrm{\rho m}$

Assertion : An important feature of Fluorite structures is that cations being large in size occupy FCC

lattice points whereas anions occupy all the tetrahedral voids giving the formula unit $A{B}_2$(A: cation B: anion).

Reason : There are 6 cations and 12 anions per FCC unit cell of the Fluorite structure.

Assertion : In NaCl crystal each Na ion is touching 6 $C{l}^{‐}$ ions but these $C{l}^{‐}$ ions do not touch each other.

Reason : The radius ratio roe $r_{Na}/r_{Cl-}$ is greater than 0.414, required for exact fitting.

Assertion : The ratio of $Z{n}^{2+ }$and F- per unit cell of ZnS and $Ca{F}_2$ is 1:2. 

Reason : In ZnS $Z{n}^{2+}$ ions occupy alternate tetrahedral voids and in $Ca{F}_2$ F- ions occupy all the tetrahedral voids of FCC unit cell.

Sodium metal crystallizes in bcc lattice with cell edge $=4.29 \stackrel{0}{A}$. The radius of sodium atom will be-