Question

Which of the following is an example of an ionic crystal solid?
(a) Diamond
(b) \[LiF\]
(c) \[Li\]
(d) Silicon

Answer 1

Hint: The solid crystals in which the oppositely charged ions (cations and anions) are linked together by a strong electrostatic force of attraction is known as ionic crystal. For \[NaCl\] and \[KCl\] are the examples of ionic crystals in which the cations (\[N{a^ + }\] and \[{K^ + }\]) are linked with anion by the electrostatic force of attraction.

Complete Step by Step Solution:
Diamond is an example of a crystalline and covalent solid in which the carbon atoms are arranged in a well-defined order. In Diamond, each tetravalent carbon atom is fused with four carbon atoms, and each of these four carbon atoms is further linked with four other carbons via a covalent bond and forms a network-like structure.

Whereas the \[LiF\] is an example of an ionic crystalline solid in which the tiny electropositive lithium cation and electronegative fluoride anion (\[{F^ - }\] ) are fused together through electrostatic force of attraction. Unlike covalent solids, no orbital overlapping takes place in \[LiF\].

The lithium metal (\[Li\]) belongs to the class of crystalline metallic solid, and it has a metallic network in which \[Li\] metals are interconnected via metallic bonds.
Like diamonds, silicon also exists as a covalent solid and forms a network-like structure as occurs in the diamond.

Therefore, from the above discussion, it is quite clear that \[LiF\] is the ionic crystal solid. Whereas diamond, lithium, and silicon belong to the class of covalent and metallic solids. Hence, option (b) will be the correct answer.

Note: In diamond, each carbon atom is present in tetrahedral form with \[s{p^3}\] hybridization. Similarly in the structure of silicon, each silicon atom presents in \[s{p^3}\] hybridization.