Changes Around Us Class 6 notes - Chapter 6

Every day we come across different types of changes. Turning day into night, night into a day, rising and setting of sun and moon, changing of climate, melting of ice, and lot more. These changes occur in a minute or take a longer time. Few changes are not even noticeable.

Types of Changes

There are two types of changes- reversible and irreversible.

Reversible Change – A change which can be changed or reversed to its original state is termed as the reversible change. Melting of ice, folding of paper, evaporation of water, inflation of balloon are few examples of reversible change.

Irreversible Change – A change which cannot be changed or reversed to its original state is termed as the irreversible changes.

Examples: Cooking of rice, preparing roti, growth in a living being, burning of paper, curdling of milk are few examples of irreversible changes.

Changes are also divided into Physical and Chemical changes. These changes are classified based on their formation of new substances.

Physical Changes – A changes which affect the physical properties of a substance is termed as the physical change. These changes result in the change of state of matter, color, odor, and solubility of substances. Physical changes are usually reversible change. Melting of ice, melting of wax, boiling of water, are examples of Physical changes.

Chemical Changes- A changes which affect the chemical properties of a substance is termed as the chemical change. Chemical changes are irreversible change and many chemical changes take place for the formation of the new substances. Rusting of iron, fermentation of sugar and grapes are examples of Chemical changes.

Important Questions

  1. What are irreversible changes?
  2. Give examples for reversible changes.
  3. Explain physical and chemical changes with examples.
  4. What are slow and fast changes? Explain with examples.
  5. Explain how milk becomes paneer. Is it a reversible change.

Learn more about Changes around us from the topics given below:


Practise This Question

Which one of the following nutrient improves the immunity of the body against diseases?