Hardness and Classification Based on Hardness

Q.

Which is the natural hardest substance?

1. Diamond

2. Iron

3. Wurtzite Boron Nitride

4. Lonsdaleite

Q. Diamond is the hardest natural occurring substance.

1. Diamond
2. Iron

Q.

Question 22

Chalk, iron nail, wood, aluminium, candle, cotton usually look different from each other. Give some properties by which we can prove that these materials are different.

Q.

The hardest known naturally occurring substance on Earth is ______ (fullerene/diamond).

Q.

Question 16

Which among the following materials would you identify as soft materials and why ?

Ice, rubber band, leaf, eraser, pencil, pearl, a piece of wooden board, cooked rice, pulses and fresh chapati.

Q. Match the following objects with the materials they are made up of.

$\begin{array}{cc}\text{Objects}& \text{Materials}\\ \text{1. Cups}& \text{a) Wood}\\ \text{2. Chair}& \text{b) Glass}\\ \text{3. Book}& \text{c) Leather}\\ \text{4. Shoes}& \text{d) Paper}\end{array}$

1. 1-c, 2-d, 3-a, 4-b
2. 1-b, 2-a, 3-d, 4-c
3. 1-a, 2-c, 3-b, 4-d
4. 1-b, 2-a, 3-c, 4-d

Q. Door locks are made of metals. Here, which property of metals is made use of?

1. Lustre
2. Opacity
3. Hardness and strength
4. Colour

Q. Knives that we use in the kitchen are made of steel because of its:

1. hardness
2. shine
3. flexibility
4. softness

Q. Choose the correct option based on the statements given below.
Statement 1: Hammer is made of iron.
Statement 2: Iron is a hard material.

1. Statement 1 is true and statement 2 is false.
2. Statement 1 is false and statement 2 is true.
3. Both statement 1 & 2 are false.
4. Both statement 1 & 2 are true.

Q. Which of the following materials are smooth?

1. Iron
2. Cotton
3. Sponge
4. Aluminium

Q.

Pick the right order based on their hardness - wood, iron, paper.

1. iron $>$ paper $>$ wood

2. iron $>$ wood $>$ paper

3. paper $>$ wood $>$ iron

4. wood $>$ paper $>$ iron

Q. Which among the following is the hardest substance?

1. Wood
2. Cheese
3. Iron
4. Plastic

Q. Door locks are made of metals. Here, which property of metals is made use of?

1. Hardness and strength
2. Colour
3. Lustre
4. Opacity

Q. _______ is the hardest known substance.

1. Graphite
2. Diamond
3. Tungsten
4. Fullerene

Q.

Write about the properties and uses of the hardest natural material?

Q.

Question 10

Find the odd one out from the following.

(a) Tawa

(b) Spade

(c) Pressure cooker

(d) Eraser

Q. Most rubber bands and tyres are made of rubber. This is because rubber is:

1. naturally available
2. an electrical insulator
3. cheap
4. elastic and strong

Q.

IS ANYTHING STRONGER THAN DIAMOND?

Q.

What are the properties of different objects or metals we

Q. Which amongst the following is not made up of rubber?

1. Erasers
2. Tyres
3. Marbles
4. Tennis balls

Q.

Give two uses of diamond.

Q.

Which is the hardest non - living thing in the world?

Q. You are provided with the following four materials like wood, plastic, wool, and steel. Which of the given material will you identify as hardest and softest respectively?

1. Wood and wool
2. Plastic and steel
3. Wool and steel
4. Steel and wool

Q. Which amongst the following is not made up of rubber?

1. Erasers
2. Tyres
3. Marbles
4. Tennis balls

Q. One fine day John was cleaning utensils. He found that the sponge used for cleaning utensils can be compressed easily but the utensils cannot be compressed. He grouped utensils and sponge in two groups. On the basis of which of the following properties, can the utensils and sponge be sorted?

1. Solubility
2. Transparency
3. Hardness
4. Appearance

Q. Sort the following substances in the increasing order of hardness.

1. Sponge
2. Eraser
3. Wood
4. Coin
5. Diamond

Q.

Which among the following would you identify as soft materials and why?​

Ice, rubber band, leaf, eraser, pencil, pearl, piece of wooden board, cooked rice, pulses, and fresh chapati.​

Q. Door locks are made of metals. Here, which property of metals is made use of?

1. Lustre
2. Opacity
3. Colour
4. Hardness and strength

Q. Which among the following is the hardest substance?

1. Wood
2. Plastic
3. Cheese
4. Iron

Q. Which among the following is hard in nature?

1. Sponge
2. Tooth paste
3. Diamond
4. Foam