Question

Which of the following does not belong to the group formed by the others?
A. Aluminum
B. Salt solution
C. Ceramic articles
D. Silver

Answer 1

Hint:Check the properties of all the material given in the options carefully. There are the materials given in the options which are good conductors of electricity. Check which of the materials given in the options are good conductors of electricity and which are bad conductors of electricity. Hence, determine the correct answer.

Complete answer:
Aluminum is a metal. In the metals, there are free electrons in the valence electrons in the valence shell of the atoms. These electrons are able to conduct electricity when a charge is applied to the metal. In the aluminum atom, there are three valence electrons in the outermost shell. Hence, aluminum is a good conductor of electricity.

Salt solutions such as sodium chloride (\[NaCl\]) conducts an electric current because it has ions in it that have the freedom to move about in the solution. These ions are produced when sodium chloride dissolve in pure water to produce sodium (\[N{a^ + }\]) and Chloride ions (\[C{l^ - }\]). Hence, the salt solutions are also good conductors of electricity.

For a material to be a good conductor, there must be a large number of atoms in the valence shell of the atoms of that material. The atoms of silver contain a large number of movable atoms or free electrons. Hence, silver is a good conductor of electricity.

The atoms in the ceramic articles are bound together tightly with the ionic bonds and there are no free electrons in the outermost shell of the atoms of ceramic to conduct electricity. Hence, ceramic articles cannot conduct electricity. Hence, ceramic articles are a bad conductor of electricity. That is why ceramic articles are different as ceramic articles are insulator while others are conductor.

Hence, the correct option is C.

Note:The students may get confused in the given options because some of the ceramic materials are good conductors of electricity. But the students should keep in mind that if we consider a broad group of the ceramic articles, almost all except a few materials are bad conductors of electricity. Hence, the ceramic materials can be assumed as bad conductors of electricity.