Class 6 Science Chapter 4 Sorting Materials into Groups, Introduction Existence of Materials, Archimedes Principle (For CBSE, ICSE, IAS, NET, NRA 2022)

Get unlimited access to the best preparation resource for CBSE/Class-6 : get questions, notes, tests, video lectures and more- for all subjects of CBSE/Class-6.

Sorting Materials into Groups

Introduction

  • Objects that we see around us are made up of a large variety of materials.
  • One object could be made up of a single material or of many different types of materials.
  • Different types of materials inhibit different properties.
  • Materials have been grouped together based on similarities and differences.
  • Materials like Paper, Oil, Wood, etc. float on water whereas materials like Stone, Bricks, etc. sink.

Reason Behind Objects Floating or Sinking in Water

Reason Behind Objects Floating or Sinking in Water
  • Objects like iron stone sinks in water since its density is greater than the water. Also, the buoyant force is less than the force exerted due to weight of the stone.
  • Buoyant force is the upward force a fluid exerts on an object.
  • Objects like Cork float on water surface since density of the cork is lesser or equal to the density of the water. In this case the buoyant force is more than the force exerted due to the weight of the cork.

Existence of Materials

  • Some materials may have shiny appearance while others are not.
  • Some of the materials are rough while some of them are smooth.
  • Some materials are hard while some are soft.
  • Materials can be soluble as well as insoluble.
  • Materials can be translucent, transparent, and opaque.

Appearance

  • Appearance of materials depends on colour, hardness, texture, and lustre.
  • Metals such as gold, silver, copper, etc. have lustre or shine.
  • Paper, wood, chalk, cotton, plastic, etc. have dull appearance.

Hardness

  • Hard materials cannot be compressed for e. g. , steel, rock, and iron.
  • Soft materials can be compressed for e. g. , rubber, and sponge.

Transparent, Opaque and Translucent

  • Transparent materials allow light to pass through them for e. g. , glass, water, etc.
  • Opaque materials do not allow light to pass through them for e. g. , wood, iron, etc.
  • Those materials which allow light to pass through them partially are known as the translucent materials for e. g. , wax paper, butter paper, etc.

Solubility or Insolubility

  • Soluble materials get easily dissolve in water for e. g. , salt, sugar, etc.
  • Insoluble materials do not dissolve in water for e. g. , flour, sawdust, etc.
  • Some liquids for example Vinegar mixes well in water whereas Mustard Oil, Coconut oil doesn՚t.

Objects and the Materials They Are Made Of

Objects and the Materials They Are Made
ObjectsMaterials they are Made of
Plate (thali)Steel, glass, plastics (any other)
PenPlastics, metal

Different Types of Objects Made from Same Material

Different Types of Objects Made from Same Material
MaterialObjects Made of these Materials
WoodChair, table, plough, bullock cart and its wheels.
PaperBooks, notebooks, newspapers, calendars.

Solid Liquid & Gas

Solid Liquid & Gas
SolidLiquidGas
Definite shape and definite volume.Indefinite shape but definite volume.Indefinite shape and indefinite volume.
Stones, wood, plastic, common salt are the examples.Water, milk, oil, etc. are the examples.Oxygen, nitrogen, carbon dioxide, etc. are the examples.

Metals, Non-Metals, and Metalloid

  • Metals are hard and are good conductors of heat and electricity for e. g. , iron, gold, etc.
  • Non-metals are brittle and are bad conductors of heat and electricity for e. g. , coal, chalk, etc.

Archimedes Principle

This principle states that a body immersed in a fluid is subjected to an upward force equal to the weight of the displaced fluid.

Archimedes Principle Formula

Where,

is buoyant force

is density the fluid

is submerged volume

is the acceleration due to gravity?

Developed by: