Question

Which of the following pairs of elements are metalloids?
A.Germanium, sodium
B.Antimony, nitrogen
C.Tellurium, arsenic
D.Selenium, chlorine

Answer 1

Any element that possesses some properties of metals and some non-metallic properties are called metalloids. They are mostly present in the starting groups of the p-block.

Complete step by step answer:
-Germanium is a metalloid because it has the properties of both metals and nonmetals. It is a semi-conductor which means that its electrical conductivity is that between the insulators and the conductors. Sodium on the other hand is an alkali metal with high electrical conductivity.
-Antimony is again a metalloid as it has properties of both metals as well as non-metals. But nitrogen is gaseous in nature and is hence a non-metal.
-Tellurium and Arsenic are not metalloids and they have been used for semiconductor applications for this purpose.
-Selenium is less frequently recognized as a metalloid and chlorine is completely a non-metal as it is gaseous in nature and a non-conductor of heat and electricity.

Hence, the correct answer is option C, Tellurium and arsenic.

Note:
-Six elements are commonly recognized as metalloids which are: Boron, silicon, germanium, arsenic, antimony, and tellurium.
-Five elements that are less commonly recognized as metalloids are: carbon, aluminium, selenium, astatine, and polonium.
-Metalloids have shiny metal-like appearance but they are brittle and only fair conductors of electricity.
-Chemically, the metalloids behave mostly like non-metals.
-They and their compounds are used for different applications that include catalysis, flame retardants, semiconductor application, etc.