Question

Which of the following is an example of metallic crystalline solids?
(a) \[C\]
(b) \[W\]
(c) \[Si\]
(d) \[AgCl\]

Answer 1

Hint: The solid is a state of matter, in which the constituent particles remain closely packed with the minimum amount of kinetic energy. Generally, solids are recognized for their rigid and hard nature. In most cases they have cubic crystal structures.

Complete Step by Step Solution:
In metallic solids the constituents’ particles i.e., metal atoms are fused together by metallic bonds.
In metallic solids, the positively charged ions are evenly distributed in the crystal and surrounded by free mobile electrons.
In metallic solid the mobile electrons are not held between a couple of atoms i.e., they can delocalize. On the other hand, the metallic solid possesses a sea of electrons everywhere (Image 1).
 
Image 1: Structure of metallic solid.

In metallic solid each atom can share one or more electrons to the sea of mobile electrons. These behaviours cause an increase in the electrical and thermal conductivity of metallic solids.
Metallic crystalline solids are malleable and ductile i.e., they can easily convert into sheets and wires respectively.
Unlike covalent solids, they are stiff or brittle in nature because the cations can slide into the sea of electrons without breaking any bond.
Metallic solids such as copper, gold, zinc, tungsten, etc. are examples of such solids.

Therefore, option (b) will be the correct answer because silicon, carbon and \[AgCl\] are not metals. While \[W\] is a metal.

Note: The metallic solid can be pure, or they can be the combination of two or more than two metals. Bronze is alloy and it has the mixture of two metals i.e., copper and tin.