Class 06 (Science) Chapter 04 Sorting of materials into groups

 

Chapter – 04

Class – 06 (Science)

SORTING MATERIALS INTO GROUPS

We see around us, a bullock cart, a cycle, cooking utensils, books, clothes, toys, water, stones and many other objects. All these objects have different shapes, colours and uses.

    There are so many ways to put objects in different groups. We have put objects in different groups on the basis of their shape or the materials they are made from.

   All objects around us are made of one or more materials. These materials may be glass, metal, plastics, wood, cotton, paper, mud and soil.

 

Object and the material they are made of

OBJECTS	MATERIALS THEY ARE MADE OF
Plate (Thali)	Steel, glass, plastics
Pen	Plastic, metal
Pencil	Wood
Toys	Plastic, Soil, Wood

 

Different types of objects that are made from the same material.

MATERIAL	OBJECT MADE OF THESE MATERIAL
Wood	Chair, table, plough, bullock cart
Paper	Books, notebooks, newspaper, toys, calendars, envelope etc.
Leather	Shoes, Jackets, Belt etc.
Plastic	Chair, table, plough, pen, plate, toys, bottle etc.
Cotton	Clothes, Shocks, bedsheets etc
Metal	Pen, doors, window, table, chair etc.

 

** We found these objects around us are made of different materials.

** An object is made of a single material.

** An object could also be made of many materials.

** One material could be used for making many different objects.

 

Properties of materials:-

(1) Appearance:- Materials usually look different from each other. Wood looks very different from iron. Iron appears different from copper or aluminium.

       There are some similarities between iron, copper and aluminium but not with wood.

 

# Materials that have such luster are usually metals.

Ex. Iron, copper, aluminium and gold.

 

#  Some metals often lose their shine and appear dull, because of the action of air and moisture.

 

(2) Hardness:- Materials which can be compressed or scratched easily are called soft. While some other materials which are difficult to compress are called hard.

Ex. Cotton or spong is soft, iron is hard.

 

(3) Soluble and insoluble:- Some substances have completely disappeared or dissolved in water. These substances are soluble in water.

Ex. Salt, sugar etc.

 

Some substances do not mix with water and do not disappear even after we stir for a long time. These are insoluble in water.

Ex. Soil, Kerosine, oil etc.

 

# Some gases are soluble in water whereas others are not.

# Water has small quantity of some gases dissolved in it.

Ex. Oxygen gas.

 

Solubility and some common liquids in water

Liquids	Mixed well / Does not mix
Vinegar	Mixes well
Lemon juice	Mixes well
Mustard oil	Does not mix
Coconut oil	Does not mix
Kerosine	Does not mix

 

(4) Object may float or sink in water:- Some of materials that do not mix with water, floated on the surface of water.

Ex. Wood, leaves, plastics ball etc.

(5) Transparency:-

   a* Transparent:- Those substance or materials, through which things can be seen clearly are called transparent.

Ex. Glass, water, air and some plastics.

 

  b* Translucent:- The materials through which objects can be seen, but not clearly, are known as translucent.

Ex. Oily paper etc.

 

c* Opaque:- Some materials through which we are not able to see other objects. These materials are called opaque.

Ex. Wood, cardboard, metals etc.