__________ is the regular three dimensional arrangement of particles in a crystal.
a crystal
a crystal lattice
a unit cell
a solid state
Covalent network crystals have low
viscosity
volatility
melting point
boiling point
In _______ cubic unit cell, there is a structural particles within the body of the cell means the center of the cube.
Primitive
Face centered
Body centered
End centered
The constituent particles in an ionic crystals are held together by powerful
Van Der Waal's forces
Chemical bonding
Electrostatic attraction
Molecular forces
In __________ the crystal lattice has identical positive ions at its points and the mobile electrons in the inter sites between them.
Ionic
Metallic
Covalent molecular
Covalent network
________ is a point within the crystal so that an imaginary straight line drawn through it will meet the surfaces of the crystal at equal distances on each side of the point.
centre of symmetry
axis of symmetry
plane of symmetry
elements of symmetry
All ____ have a definite volume.
solids
gases
air
oxygen
Which of the following consist of molecular sheets?
diamond
graphite
sodium chloride
silicon carbide
Which covalent network crystal is an exception in electrical conductivity?
none of these
