Tag: physical properties of metals and non-metals

Questions Related to physical properties of metals and non-metals

Eventhough a cinema hall is a place prone to fire hazards, the interiors are mostly made of wood or wood based panels. Why is this so ?

  1. Wood does not catch fire easily

  2. Wood is opaque

  3. Wood can absorb sound

  4. Wood is very commonly available


Correct Option: C
Explanation:

Wood is a good sound absorber. if it will be of some different material then there will be echo(a reflection of sound) in the hall and the sound will not be clear.

Most balloons, tyres and footballs are made-of rubber. This is because rubber is:

  1. naturally available

  2. cheap

  3. an electrical insulator

  4. soft and flexible


Correct Option: D
Explanation:

Prior to rubber tires, metal and wood were the materials in use. However it was found that natural Rubber provides better cushioning, makes less noise. Further rubber deforms under weight /force which results in larger contact patch with the road than with metal/wood tires of same diameter/width. During cornering at high speeds, the deformation of sidewall and larger contact area improves the traction or grip on the road increasing safety.

Which one of the following oxidation states is not possible in metal carbonyls ?

  1. +1

  2. 0

  3. -1

  4. +2


Correct Option: B

Which of the following statements are true about metals?

  1. Valence band overlaps with conduction band.

  2. The gap between valence band and conduction band is negligible.

  3. The gap between valence band and conduction band cannot be determined.

  4. Valence band may remain partially filled.


Correct Option: A
Explanation:

Valence band overlaps with conduction band for the conductivity of metal.

What is the change in color when $ZnO$ is heated?

  1. Yellow

  2. Violet

  3. Green

  4. Blue


Correct Option: A
Explanation:
Zinc Oxide is originally a white powder. When heated up, it turns yellow but does not decompose and when it is removed from the heat it gradually goes back to its original white colour.

Hence, option A is correct.

Metals are usually:

  1. good conductors of heat

  2. good conductors of electricity

  3. good elastic substances

  4. all of the above


Correct Option: D
Explanation:
Metals have these typical physical properties:
  • Lustrous (shiny)
  • Hard.
  • High density (are heavy for their size)
  • High tensile strength (resist being stretched)
  • High melting and boiling points.
  • Good conductors of heat and electricity.
  • Elastic materials 

A needle and a knife belong to the same group because:

  1. they are transparent

  2. they are hard and magnetic

  3. they float on water

  4. they are poor conductors of heat


Correct Option: B
Explanation:

As we know that a needle and a knife both are made up of metals. 

Metals are not transparent, their density is higher than water so they sink easily in water and metals are a good conductor of heat and electricity.
But metals are hard (except some exception like $Hg,\ Na$ etc) and they are magnetic.

Metals can be beaten into thin sheets. This property is called:

  1. ductility

  2. elasticity

  3. volatility

  4. malleability


Correct Option: D
Explanation:

Malleability is a substance's ability to deform under pressure ( compressive stress). If malleable, a material may be flattened into thin sheets by hammering or rolling. Malleable materials can be flattened into metal leaf. Many metals with high malleability also have high ductility.

Metals can be drawn into thin wires, this property is called:

  1. ductility

  2. elasticity

  3. volatility

  4. malleability


Correct Option: A
Explanation:

$Ductility$ is when a solid material stretches under tensile stress. If a material is ductile it can be stretched into a wire. 


When a mechanical force is applied to a material its shape changes for a certain period of time after removing the external force it regains it shape and structure, this property of a material is called $elasticity$. Elasticity of a material is measured by Young's modulus of elasticity.


In chemistry, $volatility$ is a material quality which describes how readily a substance vaporizes. At a given temperature and pressure, a substance with high volatility is more likely to exist as a vapor, while a substance with low volatility is more likely to be a liquid or solid.

$Malleability$, a similar property, is a material's ability to deform under pressure (compressive stress). If malleable, a material may be flattened by hammering or rolling and turn into thin sheets.

Option $(A)$ is correct.

Silver jewellary turns black on long exposure to air. This is due to the formation of:

  1. $Ag _2O$

  2. $Ag _3N$

  3. $Ag _2O+Ag _3N$

  4. $Ag _2S$


Correct Option: D
Explanation:

Silver is stable in pure water and air but tarnishes when it is exposed to air or water containing hydrogen sulfide, the latter forming a black layer of silver sulfide which can be cleaned off with dilute $HCl$.

$2Ag+H _2S\rightarrow \underset {black.}{Ag _2S}+H _2$