75 free MCQs on Solid State, each with its own worked answer and explanation. Explore the ordered world of crystalline solids: unit cells, packing, defects, and how structure determines electrical and magnetic properties.
Take the timed Solid State chapterwise test →75 practice questions on Solid State, sorted Easy → Hard. Try each one first, then open its answer page for the worked explanation. Want the full theory first? Read the Solid State notes.
The three cubic unit cells: Simple Cubic has atoms only at corners; Body-Centred adds one atom at the centre; Face-Centred adds one atom at the centre of each of the 6 faces, giving the highest packing efficiency.
Q1.
The total number of three-dimensional Bravais lattices possible is:
Q2.
Which of the following is an amorphous solid?
Q3.
Amorphous solids are said to be isotropic, meaning that they are:
Q5.
The number of tetrahedral voids present in one face-centred cubic unit cell is:
Q6.
Which type of solid has ions as its constituent particles?
Q7.
What is the coordination number of an atom in a simple cubic unit cell?
Q8.
Which of the following is a characteristic of crystalline solids?
Q9.
How many atoms are present per unit cell in a face-centred cubic (FCC) lattice?
Q10.
Diamond is an example of which type of solid?
Q11.
The packing efficiency of a body-centred cubic (BCC) unit cell is approximately:
Q12.
Which solid is the best conductor of electricity?
Q13.
The number of atoms per unit cell in a body-centred cubic (BCC) arrangement is:
Q14.
Which defect is caused by a missing pair of one cation and one anion from an ionic crystal?
Q15.
Ice (solid water) is an example of which type of solid?
Q16.
What is the coordination number in a face-centred cubic (FCC) structure?
Q17.
In a simple cubic unit cell, what fraction of a corner atom belongs to that unit cell?
Q18.
Which of the following has the highest packing efficiency?
Q19.
Sodium (Na) metal adopts a BCC structure. The number of Na atoms per unit cell is:
Q20.
Which of the following is an example of a Frenkel defect?
Q21.
Which type of semiconductor is formed by doping silicon with phosphorus?
Q22.
The smallest repeating unit of a crystal lattice is called the:
Q23.
NaCl has the rock salt structure with a coordination number of:
Q24.
Which property of solids increases with increasing intermolecular forces?
Q25.
The number of octahedral voids per atom in a close-packed structure is:
Q26.
The number of atoms in the unit cell of a metal that crystallises in the hexagonal close-packed (hcp) structure is:
Q27.
In a cubic unit cell atoms occupy all 8 corners, all 6 face centres and the body centre. The number of atoms per unit cell is:
Q28.
A metal with a body-centred cubic structure has an edge length of 288 pm. The radius of its atom is about:
Q29.
The percentage of empty (unoccupied) space in a face-centred cubic close-packed structure is about:
Q30.
For an ionic solid the cation-to-anion radius ratio is 0.55. The predicted coordination number and geometry are:
Q31.
For a BCC unit cell with edge length a, the radius of the atom is:
Q32.
The density of a crystal can be calculated using the formula d = ZM/(NA × a³). If Z = 4, M = 60 g/mol, a = 4 × 10⁻⁸ cm, and NA = 6 × 10²³, what is the density?
Q33.
Which crystal system has all three axes of equal length and all angles equal to 90°?
Q34.
In an FCC unit cell, the atoms touch along the face diagonal. If the edge length is a, what is the radius of the atom?
Q35.
Which of the following correctly describes a Frenkel defect?
Q36.
The radius ratio for a coordination number of 4 (tetrahedral void) lies in the range:
Q37.
In a close-packed structure with N atoms, the number of tetrahedral voids is:
Q38.
A solid has the formula AB₂. If B ions are in FCC arrangement and A ions occupy all octahedral voids, the coordination numbers of A and B are:
Q39.
The electrical conductivity of an intrinsic semiconductor:
Q40.
ZnO on heating turns yellow because:
Q41.
Which of the following solids would conduct electricity in the solid state?
Q42.
Ferrimagnetic substances have:
Q43.
In the CsCl structure, the coordination number of each Cs⁺ and each Cl⁻ is:
Q44.
In an ionic crystal, if the stoichiometry deviates from the ideal formula (e.g., Fe₀.₉₅O instead of FeO), this is a result of:
Q45.
The energy gap in a semiconductor is typically in the range:
Q46.
If edge length a = 500 pm and the structure is FCC, the radius of the atom is:
Q47.
The packing efficiency of a simple cubic unit cell is approximately:
Q48.
Which of the following explains why ionic solids do not conduct electricity in the solid state but do when molten?
Q49.
A crystal of a compound MX has a NaCl-type structure. The radius of M⁺ = 90 pm. What should be the approximate minimum radius of X⁻ for this structure to be stable?
Q50.
How does Schottky defect affect the density of a crystal?
Q51.
In the non-stoichiometric oxide Fe<sub>0.93</sub>O, the percentage of iron present as Fe<sup>3+</sup> ions is approximately:
Q52.
Copper (atomic mass 63.5 g/mol) crystallises in FCC with an atomic radius of 128 pm. Its approximate density is:
Q53.
In a close-packed lattice of anions B, cations A occupy two-thirds of the octahedral voids. The formula of the compound is:
Q54.
Oxide ions form a ccp lattice while metal ions occupy all the octahedral and all the tetrahedral voids. The formula of the oxide is:
Q55.
When NaCl is doped with 10<sup>-3</sup> mol% of SrCl<sub>2</sub>, the number of cation vacancies per mole of NaCl is (N<sub>A</sub> = 6.022 x 10<sup>23</sup>):
Q56.
A solid AB has a rock salt (NaCl-type) structure. If all face-centred atoms of the anion are removed, what is the resulting formula?
Q57.
An element with molar mass 200 g/mol crystallises in FCC. Density = 10 g/cm³. The edge length of the unit cell is:
Q58.
In the zinc blende (ZnS) structure, S²⁻ ions form FCC and Zn²⁺ ions occupy half the tetrahedral voids. The coordination numbers of Zn²⁺ and S²⁻ respectively are:
Q59.
Which statement about band theory is correct?
Q60.
Which of the following is a ferroelectric material?
Q61.
The Schottky defect is more common in NaCl than Frenkel defect because:
Q62.
A p-type semiconductor is formed by doping silicon with boron. The majority charge carriers are:
Q63.
For a crystal of NaCl (Z = 4, M(NaCl) = 58.5 g/mol, a = 5.64 × 10⁻⁸ cm), the density is approximately:
Q64.
In an antiferromagnetic solid, adjacent magnetic dipoles are aligned:
Q65.
Which of the following oxides behaves as an n-type semiconductor?
Q66.
The number of formula units of NaCl in a unit cell with FCC arrangement of Cl⁻ ions with Na⁺ in octahedral holes is:
Q67.
Calculate the fraction of total volume occupied in a simple cubic packing (SC) if radius r and edge length a = 2r:
Q68.
A metal with BCC structure has edge length 400 pm. Its density is 5.96 g/cm³. The molar mass of the metal is approximately:
Q69.
When a small amount of SrCl₂ is doped into NaCl, the type of defect created is:
Q70.
The critical radius ratio for octahedral coordination (CN = 6) is:
Q71.
How many close-packed layers repeat to give the ccp (FCC) arrangement?
Q72.
Which of the following correctly describes a piezoelectric material?
Q73.
Heating AgCl leads to an increase in its electrical conductance because:
Q74.
In an HCP structure, the coordination number and the fraction of void space are:
Q75.
The c/a axial ratio in an ideal HCP structure is:
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