50
MCQ (Multiple Correct Answer)
Which of the following cannot be regarded as molecular solid?
A
SiC (silicon carbide)
B
AIN
C
Diamond
D
$\mathrm{I}_2$
51
MCQ (Multiple Correct Answer)
In which of the following arrangements octahedral voids are formed?
A
hcp
B
bcc
C
simple cubic
D
fcc
52
MCQ (Multiple Correct Answer)
Frenkel defect is also known as ........... .
A
stoichiometric defect
B
dislocation defect
C
impurity defect
D
non-stoichiometric defect
53
MCQ (Multiple Correct Answer)
Which of the following defects decrease the density?
A
Interstitial defect
B
Vacancy defect
C
Frenkel defect
D
Schottky defect
54
Subjective
Why are liquids and gases categorised as fluids?
Explanation
Liquids and gases have the tendency to flow, i.e., their molecules can move freely from one place to another. Therefore, they are known as fluids. e.g., glass panes fixed to windows or doors of old buildings are sometimes found to be thicker at bottom. This is due to ability of glass to flow.