Notes of Ch 4 Sorting Materials into Groups Class 6th Science

Revision Notes of Ch 4 Sorting Materials into Groups Class 6th Science

Topics in the chapter

  • Object around us
  • Properties of material
  • Appearance 
  • Solubility in water
  • Solute, solvent and solution
  • How are material grouped
  • What is shorting?
  • Grouping on the basis of similarity and differences 
  • Advantage of classification

Object Around Us

→ Objects are made up of one or more materials.

→ One material can be used to make different type of objects.

→ It may be man-made or naturally occurring.

→ Material is a substance which is used to make different objects.

Properties of materials

→ Material occupy space.

→ Materials have mass.

• Material can be classified on the basis of physical state as:
(i) Solid
Examples:  sand, steel and stone.

(ii) Liquid
Examples:  oil, water and milk.

(iii) Gas
Examples: steam, nitrogen and oxygen.

General properties of material


→ Lustrous (all metals are lustrous, some are more and some are less).

→ Non-lustrous (wood, rubber and piece of rock)

Hardness (Hard and soft)

→ Brittle (break into small pieces or become powdered when hammered. Eg: - glass and salt)

→ Malleable (spread into sheets when beaten. Metal are malleable

→ Ductile ( which can draw into thin and long wire)


→ Transparent (Materials that allow the entire light pass through it, like glass, water etc.)

→ Translucent (Materials that allow some light to pass through it, like coloured glass, oiled paper.)

→ Opaque (The material which do not allow light to pass through it, like stone, wood etc.)


→ Good conductor (Metals are good conductor ; electricity can pass through it)

→ Bad conductor (non-metals ; electricity can’t pass through it)


→ Good conductor (metals are good conductor)

→ Bad conductor (non-metals are bad conductor)

Materials may float and can sink in water

→ Material which sinks in water is denser than water

→ Material which floats on water is less dense than water.

Solubility of a substance in water

→ The substance like salt and sugar which disappear in water are called as soluble.

→ The substances which don’t disappear in water are known as insoluble in water.

Miscible and immiscible liquid

→ When two liquid mixed and they do not mixed well is known as immiscible.

→ The liquids which mix well with water are said to be miscible.

Solute, solvent and solution?

→ The substances which dissolve in water are called solute.

→ A solvent is a substance that dissolves the solute to make the solution.

→ The mixture of solute and solvent is called solution.

How are material grouped

• The materials which are similar in one or two ways can be put in one group.

→ Things made from wood.

→ Things made from fibre.

→ Things made from metal.

→ Things made from ceramic.

→ Things made from glass.

→ Things made from plastic.

→ Things made from rubber.

→ Things that are liquids such as oil.

Advantages of classification

→ Helps in identifications of objects.

→ Helps in sorting of objects.

→ Helps in locating things.

→ Makes study of different objects easy and more meaningful rather than studying each other separately.

→ Helps to understand similarities and dissimilarities among objects.


Get Offline Ncert Books, Ebooks and Videos Ask your doubts from our experts Get Ebooks for every chapter Play quiz while you study

Download our app for FREE

Study Rankers Android App Learn more

Study Rankers App Promo