-
Changes occur everywhere around us.
-
For example: our mother cooking food is changing the properties of the various vegetables.
- Some changes can be reversed while few changes cannot be reversed.
-
For example: We cannot get the raw vegetables back after cooking a dish. This is irreversible i.e cannot be reversed.
- Change may occur by heating a substance or by mixing it with another substance.
- We need to study changes around us so that we have basic knowledge about the different types of materials around us.
- It can also help us in reusing materials whose changes can be reversed.
The various kinds of changes includes:
- Slow and Fast Change
- Reversible and Irreversible Change
- Desirable and undesirable change
- Physical and chemical change
Desirable and Undesirable Changes
Desirable Changes:
-
Those changes
which are desired to occur that's we would like them to take place.
- These changes help us or the nature in certain way.
For example:
-
Ripening of fruits,
- Germination of seeds
Undesirable changes:
-
Those changes
which we don't want to take place.
- These changes are not helpful to either humans or nature at large.
For Example:
-
Rusting of iron,
-
souring of milk,
- rotting of fruits