Table of Contents

SORTING MATRERIAL INTO GROUPS

Matter

Matter is anything that occupies space and has mass along with it.

Material

The matter of which an object is made is called material.
All the objects are made up of one or more materials. For ex: table is an object which is made of wood, so wood is a material.

How are Materials grouped?

The materials which are similar in one or two ways can be put in one Group: –

Things made from fiber.
Things made from wood.
Things made from rubber.
Things made from plastic.

Classification: –

The process of sorting and grouping things according to some basis is called classification.

Advantages of classification: –

It helps in the identification of objects.
It helps to understand similarities and dissimilarities between the objects around us.
It helps in the sorting of the objects.
It makes the study of different objects easy and meaningful.

Materials are classified into various group based on their properties such as appearance, texture, hardness, solubility and transparency.

1.Appearance: materials are classified on the basis of their color, size and shape.

2.Texture: Material can have smooth, rough or hard texture.

3.Hardness: some materials are hard, while other are soft.

4.solubility: materials can dissolve in water and other solvent.

5.Transparency: Materials can be transparent, translucent or opaque.

Transparent: objects through which light may pass ex: glass
Translucent: objects through which light may pass partially ex: butter paper.
Opaque: objects through which light does not pass ex: wall, wood

Good and bad conductor of electricity

Materials that allow electric current pass them easily is the good conductor of electricity. For ex metals are good conductor of electricity. Materials that do not allow electric current pass through them is the bad conductor of electricity. For ex: plastic and wood.

HEAT

Metals are good conductor of heat non metals are bad conductor of heat.

Materials may float and can sink in water

Density is a characteristic property of a substance. The objects that float in water has low density than water. Ex: leaf, sponge . If the material has a higher density than water, it sinks into water. ex: coin, stone

Solubility of substance in water

The substance like salt and sugar which dissolve in water are called as soluble.
The substance like sand which do not dissolve in water are known as insoluble in water.

Miscible and immiscible liquid

The liquid which mixes well with water are said to be miscible.
When two liquid mixed and they do not mix well is known as immiscible.

Solute, solvent and solution

Solute: The substance which dissolve in water is called solute.
Solvent: A solvent is a substance that dissolves the solute to make the solution.
Solution: The mixture of solute and solvent is called solution.

SOME EXAM RELATED QUESTION

1.Why is mercury is used in making thermometer?

It is a good conductor of heat
Mercury has luster, so it is easy to read the temperature shown in the mercury.
Mercury is liquid at room temperature.

2.List three liquids that are transparent?

Ans. Water, Alcohol, Acetone.

3. Why is water called universal solvent?

Ans. The property of water to dissolve large number of materials makes it a universal solvent.

4.Why do we need to group materials?

Ans. We often group materials for our convenience.

5.Why some materials lose their shine and appear dull?

Ans. Some material often lose their shine and appear dull because of the action of air and moisture on them.

6.kerosene, coconut oil, mustard oil does not dissolve in water, even on shaking. They separate after sometime forming two different layers explain.

Ans. The molecules of water do not mix with the molecules of oil. The space between the molecules of water is not taken by oil, so they are immiscible in water.

1.Appearance: Materials are classified on the basis of their color, size and shape.

2.Texture: Material can have smooth, rough or hard texture.

3.Hardness: Some materials are hard, while other are soft.

4.solubility: Material s can dissolve in water and other solvent.