Reversible and irreversible changes


REVERSIBLE AND IRREVERSIBLE CHANGES


•    Changes that occur around us can be broadly categorized as reversible and irreversible depending on whether or not they can be reversed.

•    Ice can be changed back to water by melting and the paper boat can be unfolded to get the sheet of paper; so these are reversible changes.

•    On the other hand, the fruit cannot be changed back to a flower and the chapatti cannot be changed back to dough; so these changes are irreversible changes.

•    Rusting of iron and growth of a plant are examples of irreversible changes.

 

Reversible Changes:

•    Those changes which can be reversed are called reversible changes.

•    Reversible changes are temporary.

 

Examples:

Melting:

•    Melted chocolate can be changed back into solid chocolate by cooling.

•    Molten ice cream can be changed back to its solid form.

•    Thus, melting is a reversible change.

•    Melting of butter and chocolate are also reversible.

 

Freezing:

•    Freezing is a reversible change.

•    We can freeze orange juice to make ice lollies.

•    The ice lollies can be changed back into orange juice when kept at a room temperature.