Tag: uses of metals and non metals

Questions Related to uses of metals and non metals

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 $HCl$.

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

Most of the metals:

  1. are hard

  2. have lustre

  3. are good conductors of electricity

  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. It can be followed that all of the above are correct

A metal which can be cut with a knife is:

  1. iron

  2. sodium

  3. copper

  4. zinc


Correct Option: B
Explanation:

Sodium and Potassium metals are the two metals which are soft and can be cut with a knife.

Why are metals solid in state?

  1. The atoms are attached by weak van der waals forces

  2. They gain electrons very easily

  3. They have a high boiling point

  4. They have a high intermolecular forces


Correct Option: D
Explanation:

Most metals are solids because the intermolecular forces between the atoms of metals are quite large. This reduces the interstitial space and so they acquire a definite shape. Room temperature is not enough to provide them required kinetic energy to overcome their forces of attraction or convert its state. Thus, they remain solid at room temperature.

Greyish white metal which is a good conductor of electricity and heat , has a boiling point of $920^\circ C$ is :

  1. aluminium.

  2. tin.

  3. iron.

  4. zinc.


Correct Option: D
Explanation:

Greyish white metal which is a good conductor of electricity and heat and has a boiling point of $920^\circ C$ is zinc.


Hence, the correct option is $D$.


Zinc has a melting point of :

  1. $233^\circ C$

  2. $219^\circ C$

  3. $333^\circ C$

  4. $419^\circ C$


Correct Option: D
Explanation:

The metal Zinc has a melting point of $419^\circ C$.

A bar of zinc generates a characteristic sound when bent, similar to_________.

  1. Tin cry

  2. Water splashing

  3. Glass breaking

  4. None of above


Correct Option: A
Explanation:

A bar of zinc generates a characteristic sound when bent, similar to tin cry. A tin cry is the characteristic sound heard when a bar of tin is bent. Variously described as a "screaming" or "crackling" sound, the effect is caused by the crystal twinning in the metal.