Tag: nature of things

Questions Related to nature of things

A block of iron (density 9.8 $ \displaystyle g/cm^{3}) $ if added in mercury (density 13.6 $ \displaystyle g/cm^{3} $ ) will:

evs nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. sink

  2. float

  3. neither float nor sink i.e. remain suspended in mercury

  4. none of these

Show answer
Correct Option: B
Explanation:

The average density of the object should be less than the density of the fluid in which the object has to float.


The density of object (iron) is less than the fluid (mercury).

Therefore, it will float.


Hence, option B is correct.

A block of aluminium of density 2.75 $ \displaystyle g/cm^{3} $ has a volume of 30$ \displaystyle cm^{3} $. The mass of the block is:

evs nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. $27$ gm

  2. $18 $ gm

  3. $82.5$ gm

  4. $810$ gm

Show answer
Correct Option: C
Explanation:

Mass $=$ Density $\times$ Volume

So, Mass of aluminium $=2.75 \times 30 = 82.5\  gm$
Hence, option $C$ is correct.

A block of wood has mass 200 kg. If the density of wood is 800 $ \displaystyle kg/m^{3} $, its volume will be:

evs nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. 0.25 $ \displaystyle  m^{3} $

  2. 25 $ \displaystyle  m^{3} $

  3. 250$ \displaystyle  cm^{3} $

  4. none of these

Show answer
Correct Option: A
Explanation:
Volume = Mass/ Density
So, volume of wood = 200/800 = 0.25 $m^3$

Identify the materials from the following which float in water: 

evs nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. wax, iron nails, sponge

  2. plastic, wood, oil

  3. ice, oil, sand

  4. honey, thermocol, keys

Show answer
Correct Option: B
Explanation:

Things which are lighter than water or less dense than water will not sink in water eg. plastic, wood, and oil.

Opaque objects:

evs nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. does not transmit most of the light falling on them

  2. transmit most of the light falling on them

  3. absorb most of the light falling on them

  4. are strong and hard

Show answer
Correct Option: C
Explanation:

An opaque object is neither transparent (allowing all light to pass through) nor translucent (allowing some light to pass through). When light strikes an interface between two substances, in general, some may be reflected, some absorbed, some scattered, and the rest transmitted. 

Transparent substances:

evs nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. absorb all the light incident on them.

  2. allow light to pass through them.

  3. do not allow light to pass through them.

  4. allow light to pass through them only partially.

Show answer
Correct Option: B
Explanation:

Transparent substances allows the light to pass through them. Due to this it is possible to see through the transparent substances. 

Example: We are able to see through the some glasses because they are transparent.

Which of the following is translucent?

chemistry nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. Copper

  2. Wood

  3. Butter paper

  4. Glass

Show answer
Correct Option: C
Explanation:

The material through which light can pass partially is called translucent, e.g. butter paper, thin curtain, tinted glass etc.

Find the odd man out in terms of material it is made of:

chemistry nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. Rubber

  2. Gold

  3. Coal

  4. Chalk

Show answer
Correct Option: B
Explanation:

Coal, chalk and rubber all are non-metals but gold is metal with lustre and is the good conductor of heat and electricity whereas non-metals are bad conductors of heat and electricity.

Which of the following has dull appearance?

chemistry nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. Gold foil

  2. Aluminium foil

  3. Steel rod

  4. Bricks

Show answer
Correct Option: D
Explanation:

The appearance of an object depends on color, hardness, texture, and luster of its material. Materials which are made up by non-metals have dull appearance eg. bricks.

Select the metal which is hardest among the following:

chemistry nature of things properties of materials grouping and classification of objects sorting materials into groups

  1. silver

  2. gold

  3. platinum

  4. aluminium

Show answer
Correct Option: C
Explanation:

As the size of the metal increases, they become harder.

So, size of the metals- $Al < Ag < Au < Pt$
As we move across the period size decreases hence $Pt>Au$. 
$\therefore$ $Pt$ is hardest.