Q.1.
The number of nearest particles which is in direct contact with a particle in a closed packed structure
Q.2.
Which of the following is a network solid?
Q.3.
In both HCP and CCP the coordination number is
Q.4.
A. Ionic solids are hard and brittle. B. Covalent solids are good conductors.
Q.5.
What is the packing efficiency of FCC unit cell ?
Q.6.
A compound is formed by A and B in which A occupies all corners and B occupies all face centres. What is the formula of the compound?
Q.7.
Which compound show both Schottky and Frenkel defect?
Q.8.
If Z is the number of atoms in the cell that represents the closest packing sequence ABCABC.......... the number of tetrahedral voids in the unit cell is
Q.9.
Percentage of free space in BCC unit cell is
Q.10.
What is the Coordination numberof an atom in FCC or CCP structure ?
Q.11.
If the radius of the octahedral void is r and radius of the atoms in closepacking is R, What is the ratio between r and R.
Q.12.
What is the smallest repetitive unit of the crystal / lattice structure known as?
Q.13.
In METAL EXCESS DEFECTS the sites where an electron gets trapped in the anionic vacancy disturbing the ratio of cation to anion is known as
Q.14.
Based on the nature of intermolecular forces, classify the following solids : Silicon carbide
Q.15.
Which of the following is an amorphous solid?
Q.16.
Analysis shows that FeO has a non-stoichiometric composition with formula Fe0·95O. Give reason.
Q.17.
An element ‘X’ (At. mass =g mol–having f.c.c. structure, has unit cell edge length ofpm. Calculate the density of ‘X’ .
Q.18.
Which of the following is a network solid or covalent crystalline solid?
Q.19.
Gold (atomic radius = 0.nm) crystallises in a face-centred unit cell. What is the length of a side of the cell?
Q.20.
The type of crystalline solid which is a good conductor in solid as well as molten state?