JEE Main · 2021 · 18 Mar 2021 · Shift 2 · Solid State

WhatsApp Email

A hard substance melts at high temperature and is an insulator in both solid and in molten state. This solid is most likely to be a/an:

(A)Ionic solid
(B)Metallic solid
(C)Molecular solid
(D)Covalent solid✓ Correct

Answer: (D)

Solution

Hardness together with a high melting point points to a three-dimensional network of strong bonds, which a molecular solid with its weak intermolecular forces cannot provide. A metallic solid has mobile electrons and conducts as a solid. An ionic solid does insulate as a crystal, but melting frees its ions and the melt conducts. A solid that still insulates after melting therefore holds its electrons in localised bonds between neighbouring atoms, so it is a covalent solid.

JEE Main · 2021 · 18 Mar 2021 · Shift 2 · Single correct option

Practise more: all JEE Main PYQs on Solid State →

More JEE Main questions on Solid State

Which of the following material is not a semiconductor.
JEE Main 2024View solution →
The values of conductivity of some materials at $298.15 K^{- 1} Sm^{- 1}$ are $2.1 \times 1 0^{3}$ , $1.0 \times 1 0^{- 16}$ , $1.2 \times 10$ , $3.91$ , $1.5 \times 1 0^{- 2}$ , $1 \times 1 0^{- 7}$ , $1.0 \times 1 0^{3}$ . The number of conductors among the ma …
JEE Main 2024View solution →
A compound is formed by two elements X and Y. The element Y forms cubic close packed arrangement and those of element X occupy one third of the tetrahedral voids. What is the formula of the compound?
JEE Main 2023View solution →
Number of crystal systems from the following where body centred unit cell can be found, is.....

Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral, monoclinic, triclinic.
JEE Main 2023View solution →
The correct relationship between unit cell edge length 'a' and radius of sphere 'r' for face-centred and body centred cubic structures respectively are:
JEE Main 2023View solution →
An atomic substance A of molar mass $12 g mol^{- 1}$ has a cubic crystal structure with edge length of 300 pm . The no. of atoms present in one unit cell of A is ____. (Nearest integer)

Given the density of A is $3.0 g mL^{- 1}$ and …
JEE Main 2023View solution →