Test: Physical Properties of Metals - UPSC

The lightest or least dense metal that is a pure element is lithium, which has a density of 0.534 g/cm³. This makes lithium nearly half as dense as water, so if lithium was not so reactive, a chunk of the metal would float on water.

Silver is the best conductor of electricity among the given options because it has a relatively low electrical resistivity. The electrons in silver are able to move more freely than those of the other elements, allowing electricity to flow more easily. This is due to the structure of the silver atom, which allows for more free electrons on the outer shell. Additionally, silver has a high thermal conductivity, meaning it is able to transfer heat quickly and efficiently.

Amphoteric metal oxides react with both acids as well as bases to produce salt and water.

Aluminium oxide is an amphoteric oxide because it reacts with acids as well as bases and form salts and water.

Al₂O₃     +     6HCl     →     2AlCl₃    +    3H₂O                      (Basic nature)

Aluminium   Hydrochloric   Aluminium      Water

   oxide            acid          chloride

Al₂O₃        +       2NaOH    →      2NaAlO₂     +     H₂O           (Acidic nature)

Aluminium           Sodium              Sodium          Water

   oxide             Hydroxide          aluminate        

Heat energy is conducted by transferring energy of atoms vibrating at high level. This energy is transferred by vibrating neighboring atom. Since high density of mercury, there is no enough room for vibrating mercury atoms. So it can’t be heated easily.

It is the only metal that is liquid at room temperature. It has the lowest melting point and boiling point of any other metal. It has low thermal conductivity, and a quite low electrical conductivity. It is the only metal that doesn’t form diatomic molecules in the gaseous phase.

Sodium is an alkali metal and is so soft that it can be easily cut by knife.

Graphite is an interesting material, an allotrope of carbon (as is diamond). It displays properties of both metals, and nonmetals. However, like a metal, graphite is a very good conductor of electricity due to the mobility of the electrons in its outer valence shells.

Lead is a metal but it is a poor conductor of heat because it contain some particles which does not allows heat to pass through it .

The properties that should have for a metal are sonority, lustrous, malleability ductility, heat and electrical conductivity as dullness is not one of them it is the correct option

Non - metals do not have luster. They do not reflect light from their surface ( except iodine and diamond) . So, here a lustrous now Metal is iodine.

In our atmosphere , presence of 78 % nitrogen after then presence of oxygen 21 % others 1 %. so the abundant non metal is oxygen

Non - metals do not react with water to evolve hydrogen gas. ( no reaction)

Metals that are liquids at room temperature are mercury (Hg) and gallium (Ga). Non-metals liquid at room temperature - bromine (Br). However, other elements such as caesium (Cs), rubidium (Rb) and francium (Fr) also become liquids at a few degrees above room temperature.

The lustre of a metal is due to presence of free electrons.

It has to do with the way light and electrons on the surface of metals interact. The outer electrons in a metal are almost not bound to any individual atom, thus are relatively free, and are concentrated on the surface. These electrons (electron density) tend to oscillate at a collective frequency. 

The most ductile metal amongst the given options is Platinum.

The word ductile refers to metals which can be stretched into a thin wire without making it weak or brittle in the process.

Ductility is an indication of the ability of a metal to resist tensile stress. Tensile stress refers to the force that pulls the two ends of an object away from each other.

Gold and platinum are the most ductile metals existing on the earth. But gold has slightly more ductility than platinum.