Question

Which of the following cannot be beaten into thin sheets?
(A) Al
(B) K
(C) Ar
(D) Cr

Answer 1

Hint: Malleability is the property of substance allowing it to be drawn into thin sheets by rolling or hammering. This deformation is basically caused under specific pressure by external media.

Complete answer:
Let us know about the property of malleability and the metals which can show this property.
Malleability-
It is a physical property of materials, usually metals which can be flattened into metal leaf. It is primarily the ability of a solid to bend or be hammered to form other shapes without breaking. This property is not seen in non-metals i.e. they break into pieces when hammered.
Some common examples of malleable metals are; gold, iron, silver, aluminium, copper, lead, etc.
Sometimes, the hard metals make it harder to be deformed into thin sheets. Also, most metals which are malleable are also ductile such as copper whereas some have low ductility but high malleability such as lead.
Most of the time the property of malleability depends upon the surrounding temperature. As, some metals (ex: zinc) can be brittle in cold working temperatures but can be highly malleable at higher temperatures.
In the given illustration,
Aluminium, potassium and chromium are metals whereas argon is a non-metal (in fact noble gas). Thus, argon does not show the property of malleability.

Therefore, option (C) is correct.

Note:
Do note that pure chromium is hard, magnetic and brittle in nature but, alloyed chromium can be made malleable and polished to brighter, silvery finished form.