19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Which of the following is a molecular crystal
Bravais lattices are of
Which of the following is non-crystalline solid
Which of the following is a pseudo solid
Amorphous substances show (1) Short and long range order (2) Short range order (3) Long range order (4) Have no sharp M.P.
Amorphous solids are
Which is not a property of solids
The number of atoms or molecules contained in one body centered cubic unit cell is
How many chloride ions are there around sodium ion in sodium chloride crystal.
Ferrous oxide has a cubic structure and each edge of the unit cell is 5.0 Å. Assuming density of the oxide as 4.0 g cm–3, then the number of Fe2+ and O2– ions present in each unit cell will be
Assertion : In Schottky defects, electrical neutrality is maintained. Reason : Equal number of cation and anion vacancies are present.
Assertion : Unlike Schottky defects, Frenkel defects don’t change the density of solids. Reason : These defects are basically point defects.
Assertion : In caesium chloride structure, Cl- ions are at the corners of a primitive cubic array and Cs+ ions fits into big central empty region in each Cl- array. Reason : The radius ratio r Cs r Cl is greater tha…
Assertion : Co-ordination number of rock salt is 8. Reason : Limiting radius ratio for rock salt is between 0.414 and 0.732.
Assertion : If three elements A, B and C crystallize in a cubic solid lattice with A atoms at the corners, B atoms at the cube centre and C atoms at the centre of the faces of the cube, then the formula of the compoun…
Assertion : Packing in body centered cubic (bcc) structure is more efficient than in cubic closed packed (ccp) structure. Reason : 74% of the total space is occupied by the atoms in fcc structure while only 68% of the…
Assertion : If density of CsCl (cubic structure) is 3.99 g/cm3, the distance between Cs+ and Cl- ions will be 357 pm [atomic mass of Cs = 133]. Reason : CsCl has bcc lattice.
Assertion : Graphite is an example of tetragonal crystal system. Reason : For a tetragonal system, a = b c, α = β = γ = 90º.
In NaCl lattice the radius ratio is Na Cl r r =
Assertion : Covalent crystals have a higher melting point. Reason : Covalent bonds are stronger than ionic bonds.
Assertion : Crystalline solids are anisotropic. Reason : The constituent particles are very closely packed.
Crystalline solid is
Assertion : The window glass of the old buildings is thick at bottom. Reason : Glass is a supercooled liquid of high viscosity and has the property to flow.
Assertion : Glass is an amorphous solid. Reason : In glass, there is only short range order.
Which one of the following is a covalent crystal? [KCET 2011]