19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Among solids the highest melting point is established by
Mostly crystals show good cleavage because their atoms, ions or molecules are
A crystalline solid
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.
Crystalline solid is
Amorphous solids are
Amorphous substances show (1) Short and long range order (2) Short range order (3) Long range order (4) Have no sharp M.P.
Which is not a property of solids
Xenon crystallises in the fcc lattice and the edge of the unit cell is 620 pm. The nearest neighbour distance of Xe is
Assertion : Graphite is an example of tetragonal crystal system. Reason : For a tetragonal system, a = b c, α = β = γ = 90º.
Electrons in a paramagnetic compound are
Those substances which show permanent magnetism even in the absence of magnetic field are called
On the basis of their magnetic properties, substances can be classified into …A… categories. Here, A refers to
Assertion : Covalent crystals have a higher melting point. Reason : Covalent bonds are stronger than ionic bonds.
Identify the incorrect statement.
Doping of silicon (Si) with boron (B) leads to
Assertion No compound has both Schottky and Frenkel defects. Reason Both defects change the density of the solid. [AIIMS 2008]
An element (atomic mass = 100 g/mol) having bcc structure has unit cell edge 400 pm. Then density of the element is
The number of atoms in 100 g of an FCC crystal with density d = 10 g cm –3 and cell edge as 200 pm is equal to
Potassium has a bcc structure with nearest neighbour distance 4.52 Å. Its atomic weight is 39. Its density will be
A metal has bcc structure and the edge length of its unit cell is 3.04Å. The volume of the unit cell in cm will be
Sodium metal crystallizes as a body centred cubic lattice with the cell edge 4.29Å. What is the radius of sodium atom.
An element has a body-centred cubic (bcc) structures with a cell edge of 444 pm. The density of the element is 7.2 g/cm3. How many atoms are present in 404 g of the element?
An alloy of Cu, Ag and Au is found to have copper constituting the ccp lattice. If silver atoms occupy the edge centre and gold is present at body centre, the alloy has a formula
A compound is formed by elements A and B. This crystallizes in the cubic structure when atoms A are the corners of the cube and atoms B are at the centre of the body. The simplest formula of the compound is