Which of the following has 1.54 Ao bond length throughout the crystal?
sodium chloride
silicon carbide
graphite
diamond
Which crystal does not have free electrons for electric conduction?
ionic crystal
covalent network crystal
both (a) and (b)
none of these
In ______________ crystals, the units occupying lattice are positive and negative ions.
Metallic
Covalont
Ionic
Molecular
________________ is a good example of covalent crystal .
Diamond
Ice
Graphite
Charcoal
At what temperature the vibrational energy of the contents of the diamond increase?
4000oC
6000oC
5000oC
7000oC
Which bonds connect the carbon atoms in a diamond crystal?
valance bond
covalent bond
coordinate bond
ionic bond
How many carbon atoms surrounded each carbon atom in diamond structure?
8
2
4
6
In the Bragg's equation for diffraction of x rays n' represent
The number or moles
Avagadro number
A quantum number
Order of reflection
Which of the following is transparent?
coal
lead
Diamond is a _______ crystal.
opaque
transparent
translucent
