Solid state practice · Medium

Select the incorrect statement among the following

A compound alloy of gold and $Cu$ crystallises in a cubic lattice in which the gold atoms occupy the lattice points at the corners of a cube and the copper atoms occupy the centres of each of the cube faces. What is the empirical formula of this compound?

The effective number of carbon atoms in a unit cell of diamond is

The statement that, “It is possible to choose along the three co-ordinate axes unit distance $a,b,c$ not necessarily of the same length, such that the ratio of there intercepts of any plane in the crystal is given by in $ma:nb:pc$ where $m,n,p$ are either integral whole numbers including infinity or fraction of whole number” is known as :

Which of crystal systems contains the maximum number of Bravais lattices?

Silver metal crystallises in a cubic closed packing arrangement with the edge of the unit cell ${a}=407\, \mathrm{pm}$. The radius of silver atom is $(X+3.9) \mathrm{pm}$. Find the value of $X$.

If a crystal lattice of a compound, each corner of a cube is enjoyed by sodium, each edge of a cube has oxygen and centre of a cube is enjoyed by tungsten $(W)$, then give its formula

Which of the following substance possess antiferromagnetic property?

An ${AB}$ solid has ${CsCl}$ type of structure, where ${A}$ occupies corner. If the atoms from corners along one of the body diagonal are removed, the formula of the solid would be

A crystal of $\mathrm{F}{\mathrm{e}_3}{\mathrm{O}_4}$ is :

The number of octahedral sites per sphere in a fcc structure is

The range of radius ratio (cationic to anionic) for an octahedral arrangement of ions in an ionic solid is

Which one of the following statements about packing in solids is incorrect?

Assertion (A): In ${NaCl}$ crystal each ${Na}^{+}$ion is touching $6 \, {Cl}^{-}$ions but these ${Cl}^{-}$ions do not touch each other.

Reason (R): The radius ratio is greater than 0.414 required for exact fitting.

p-type semiconductor is formed when germanium is doped with

In a monoclinic unit cell the relation of sides and
angles are respectively:

A compound of ‘A’ and ‘B’ crystallises in a cubic lattice in which ‘A’ atoms occupy the lattice points at the corners of the cube. The ‘B’ atoms occupy the centre of each face of the cube. The probable empirical formula of the compound is

The number of equidistance oppositely charged ions in a sodium chloride crystal is

Among the following species, the one which become paramagnetic on heating at $850 {~K}$ is

The pyknometric density of sodium chloride crystal is $2.165 \times {10^3}\;\mathrm{kg}\;{\mathrm{m}^{ - 3}}$ while is X-ray density is $2.178 \times {10^3}\;\mathrm{kg}\;{\mathrm{m}^{ - 3}}$. The fraction of the unoccupied sites in sodium chloride crystal is :

Assertion : Stability of a crystal is reflected in the magnitude of its melting point.

Reason : The stability of a crystal depends upon the strength of the interparticle attractive force.

Assertion (A) Both Frenkel and Schottky defects are stoichiometric defects.

Reason (R) Both defects change the density of the crystalline solid.

Order of packing efficiency is

Structure similar to zinc blende is found in

How many number of atoms are there in a cube based unit cell having one atom on each corner and two atoms on each body diagonal of cube

In zinc blende structure, the coordination number of $\mathrm{Z}{\mathrm{n}^{2 + }}$ ion is

The number of unit cells in the Ca atom lies on the surface of a cubic crystal that is $1.0 \mathrm{~cm}$ in length is

The ratio of cationic radius to anionic radius in an ionic crystal is greater than 0.732. Its coordination number is

Which of the following statements is/are not true?

In a solid $'AB'$ having the NaCl structure $'A'$ atoms occupy the corners of the cubic unit cell. If all the face centred atoms along one of the axes are removed then the resultant stoichiometry of the solid is