The number of close neighbours in a body centered cubic lattice of identical sphere is
6
4
12
8
What is the C-C bond length in diamond?
1.31 Ao
2.6 Ao
1.54 Ao
0.86 Ao
Carbon atoms in a diamond crystal are in a state of
sp3 hybridization
sp2 hybridization
sp hybridization
sp2d hybridization
The Braggs equation is
a = 2dsinΘ
nd= 2aSinΘ
2a = nd sinΘ
nλ = 2d sinΘ
________________ is a good example of covalent crystal .
Diamond
Ice
Graphite
Charcoal
Which of the following is extremely hard?
coal
silicon carbide
coke
plastic
The ability of certain ultra cold substances to conduct electricity without resistance is called
n- type semiconductors
p- type semiconductors
Superconductors
Conductors
Which crystal vapourize at 7000oC?
sodium chloride
graphite
diamond
Which of the following is transparent?
lead
Which of the following has its atoms connected by valence bonds?
none of the above
