1.zinc blende structure
A crystal may have one or more planes of symmetry as well as one or more than one axis of symmetry but it has only no centre of symmetry.
1.two centres of symmetry
2.one centre of symmetry
3.four centres of symmetry
4.no centre of symmetry
A match box exhibits
A metal M has FCC arrangement and edge length of the unit cell is 400 pm. The atomic radius of M is
A pure crystalline substance on being heated gradually first forms a turbid liquid at constant temperature and still at a higher temperature the turbidity completely disappears. The behaviour is a characteristic of substance forming
A simple cubic lattice consists if eight identical spheres of Radius R in contact placed at the corners of the cube what fraction of the total volume of cube is actually occupied by the cube?
An atom at the edge centre of the cubic unit cell contributes??? to the particular unit cell.
An element A crystallizes by adoption AB AB AB??? pattern of close packing the number of atoms in the unit cell is
Certain intermetallic compound of lithium and silver crystallizes in cubic structure in which both Li and Ag atoms have co-ordination number of 8. To what crystal class does the unit cell belong?
Clay is an example of
4.Frame work silicate.
During evaporation of liquid
1.temperature of liquid will rise
2.temperature of liquid will fall
3.temperature of liquid may rise or fall depending upon its nature
4.temperature of liquid remains unaffected.
4.None of these.
For and atomic crystal having body centred cubic unit cells the number of atoms per unit cell is
If a is edge length of a face centred cubic unit cell then the distance of closest approach of two particles is
In a body centred cubic unit cell of a metallic substance the number of atoms per unit cell is
In a close packing the radius of the octahedral void relative to the radius of the spheres constitution it is
In a cubic crystal anions are arranged in FCC and the cations occupy half the tetrahedral voids and all the octahedral voids. The ratio of cations and anions in the crystal is
In a face centred cubic lattice the number of nearest neighbours for a given lattice point is
In a metal M having BCC arrangement edge length of the unit cell is 400 pm. The atomic radius of M is
In antifluorite structure what percentage of the tetrahedral voids is occupied by cations?
In hexagonal close packing of spheres in three dimensions the co-ordination number of each spheres is
4. 12 6
4.In all the three arrangements the density would be same.
1.half the edge length
2.half the face diagonal
3.3/4 th of body diagonal
1.equal number of cation and anion vacancies
2.interstitial anions and anion vacancies
3.cation vacancies only
4.cation vacancies and interstitial cations.
NaCl is an example of
Number of mirror planes in a cube is
Potassium crystallizes with
3.simple cubic lattice
Pure silicon doped with phosphorus is
1.nature of liquid
4.Size of vessel.
The Edge length of face centred cubic unit cell is 508 pm. If the radius of cation is 110 pm the radius of anion is
The intermetallic compound LiAg crystallizes in cubic lattice in which both lithium and silver have co-ordination number of 8. The crystal class is
2.body centred cube
3.face centred cube
4.end centred cube.
The number of octahedral and tetrahedral voids per sphere in a cubic close packed arrangement is respectively.
1.1 and 3
2.6 and 4
3.1 and 2
4.2 and 1.
The percentage of the available space occupied in a hexagonal close packing of spheres in three dimensions is
What is not true about amorphous solids? I. They undergo clean cleavage II. They do not have sharp melting pointsIII. They have high degree of rigidityIV. They exhibit isotropy. I
What is true about solids? I. Interparticle distance is minimumII. K.E. of particles is highIII. Interparticle attraction is largeIV. All solids have sharp mp and bp.
1.I II III
2.Metal excess defect due to anion vacancies
3.Metal excess defect due to extra cation
When a cation and an anion are missing leaving behind a pair of voids the defect is known as:
4.None of these.
When a cation leaves its normal position in the crystal and moves to some interstitial space the defect in the crystal is known as
When electrons are trapped in the crystal lattice in place of anion vacancy the defect in the crystal is known as
2.Sodium potassium tartrate
3.Sharp melting point
1.NaBr Ad Br
Which type of silicates involve sharing of two oxygen atoms between silicon atoms?I. single chain silicate II. ring silicateIII. sheet silicate IV. double chain silicate.