The property of crystalline solid is not

Wax is an example of

Which one of the following is a molecular crystal ?

In a tetragonal crystal

An example of a face centered cubic lattice is

Conductivity of silicon increases on doping it with phosphorus. Why

A solid with cubic crystal is made of two elements 'P' and 'Q'. Atoms of 'Q' are at the corners of the cube and 'P' at body centre. What is formula of compound?

A cubic solid is made of two elements X and Y. Atoms Y are at the corners of the cube and X at the body centre. What is the formula of the compound?

How many atoms can be assigned to its unit cell if an element forms
(i) a body-centred cubic cell, and
(ii) a face-centred cubic cell?

Why is glass considered as supercooled liquid?

Name the non-stoichiometric point defect responsible for colour in alkali halides.

Name an element with which silicon can be doped to give a p-type semiconductor.

Name the crystal defect which lowers the density of an ionic crystal.

What makes the crystal of KCI appear sometimes violet?

What is the effect of Schottky and Frenkel defects on the crystaline solids?

Why are liquids and gases categorised as fluids?

Why are solids incompressible?

Why does table salt, NaCl sometimes appear yellow in colour?

With the help of a labelled diagram show that there are four octahedral voids per unit cell in cubic close packed structure.

Show that in cubic packed structure, eight tatrahedral voids are persent per unit cell.

Copper crystallises with face-centred cubic unit cell. If the radius of copper atom is 127.8 pm, calculate the density of copper metal.(Atomic mass of Cu = 63.55 u and Avogadro's number, N_A = 6.02\(\times \) 10²³ MOL^-1)

What are ferromagnets and ferro-electrics? Give on example of each case.