Question

Among the following pair, the one containing the examples of metalloid elements in the periodic table is:
(A).Na and K
(B).F and Cl
(C).Cu and Ag
(D).B and Si

Answer 1

To solve this question we should know the difference between metals, nonmetals and metalloids. So we will observe all the options one by one and find out which of these have the same properties as those of metalloids.

Complete answer:
The metalloids are intermediate in their properties to metals and non-metals. In their physical properties, they are more like non metals but under certain circumstances they can be made to conduct electricity. The metalloids are referred to as semiconductor elements. These are very important in computers and in other devices.
Chemically the metalloids correspond to atoms having intermediate electronegativity and it has an ability to display a range of both positive and negative oxidation states in their compound.
In the above given options B and Si are metalloids. These elements fulfil all the properties of metalloids.

Hence the correct answer is option (D).

Additional information:
Metals are the good conductors of heat and electricity. They are malleable which means that they can be hammered into sheets and ductile which means that they can be drawn into wires. Most of the metals are usually solid at room temperature.
Non-metals are poor conductors of heat and electricity and they are neither malleable nor ductile. Mainly the non-metals are gases at room temperature.

Note:
The term metalloids is normally applied to a group of between six to nine elements i.e. born, silicon, germanium, arsenic, antimony, tellurium, bismuth, polonium and astatine. They are present at the middle of the periodic table.