Changes Around Us Class 6 Notes Science Chapter 6

Changes Around Us Class 6 Notes Science Chapter 6

Learn from School Connect Online in this chapter, we will learn topics like changes from day to night, night to a day, rising and setting of sun and moon, changing of climate, melting of ice, and a lot more. Some changes are quick while others take time. Lets study and explore more of such interesting phenomena in this chapter.

CBSE Class 6 Science Notes Chapter 6 Changes Around Us

CBSE Class 6 Science Notes Chapter 6 Changes Around Us

The different topics covered in CBSE Class 6 Science Chapter 6 are tabulated below:

Ex-6.1Can All Changes Always Be Reversed?
Ex-6.2Could There Be Other Ways To Bring A Change?

Ex. 6.1 – Can All Changes Always Be Reversed?

Changes caused by heating: When an object is heated, it gets affected in one or many possible ways.

  • Some objects get hot but do not change in any other way.
  • Some objects get hot and also expand in size.
  • Some objects get hot and begin to bum.
  • Some objects get hot and change their state.

Changes by applying pressure: When we apply force to an object:

  • We can change its shape and size.
  • Air can be compressed.
  • Metals can be hammered into thin sheets.
  • Elastic can be stretched.
  • Cotton can be spun into thin threads.

Chemical changes: These are the changes in which chemical properties of a substance change, and a new substance is formed. For example, cooking food.

Characteristics of chemical changes:

  • Properties of products are different from the properties of reactants.
  • Most of the chemical changes are irreversible.
  • These changes always result in energy changes.

Physical changes: These are the changes in which only physical property of a substance changes and no new substance is formed.Characteristics of physical changes:

  • No new substances are formed.
  • Products are identical to the reactants.
  • These changes are reversible.

Reversible changes: These are the changes that can be reversed.

For example : stretching of rubber

Irreversible changes: These are the changes which cannot be brought back to its original state.

For example : burning paper

Ex. 6.2 – Could There Be Other Ways To Bring A Change?

Melting: A process in which a solid melts to become a liquid on heating is called melting.

Melting point: A constant temperature at which a solid starts melting. This temperature is called the melting point of that solid.

Freezing: A process in which liquid changes into solid form is called freezing.

Changes: Many changes are taking place around us on their own, e.g., flowers bloom and then wither away. We can also bring a change, e.g., change in the size of a balloon by blowing air in it.

Natural changes: The changes which occur in nature on their own are called natural changes. For example, change of day and night, change of season.

Slow changes: The changes which take longer time to occur are called slow changes. For example, rusting of iron, tooth decay.

Contraction: A process in which an object becomes smaller or shrinks is called contraction.

Evaporation: A process in which liquid changes into vapour is called evaporation.

Expansion: A process in which an object becomes bigger in size, e.g. metals expand on heating.

Separation : The separation of the components of a mixture or an impure substance are carried out with the following purposes :

a. To remove the unuseful or harmful component.

b. To obtain the useful component.

c. To remove impurities for getting a pure sample.

Conclusion :

  • Changes happen around us and also within us.
  • Some changes are reversible, while some others are irreversible.
  • Some changes are physical changes; some are chemical changes.
  • Heating causes expansion in a material.
  • Cooling causes contraction in a material.
  • Gases expand the most and solids expand the least.
  • Gases contract the most and solids contract the least.

CBSE Notes for Class 6 Science Free Download for All Chapters

CBSE Class 6 Science Study NotesCBSE Class 6 Science Study Notes
Food: Where Does It comes from? Class 6 notes – Chapter 1The Living Organisms And their Surroundings Class 6 notes – Chapter 9
Component of Food Class 6 notes – Chapter 2Motion and Measurement of Distances Class 6 notes – Chapter 10
Fibre to Fabric Class 6 notes – Chapter 3Light, Shadows and Reflection Class 6 notes – Chapter 11
Sorting Materials Into Groups Class 6 notes – Chapter 4Electricity and Circuits Class 6 notes – Chapter 12
Separation of Substances Class 6 notes – Chapter 5Fun with Magnets Class 6 notes – Chapter 13
Changes around Us Class 6 notes – Chapter 6Water Class 6 notes – Chapter 14
Getting to Know Plants Class 6 notes – Chapter 7Air Around Us Class 6 notes – Chapter 15
Body Movements Class 6 notes – Chapter 8Garbage In, Garbage Out Class 6 notes – Chapter 16

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