Some changes are temporary while some other are permanent .

Some changes produce new substance while others do not .

Some changes are natural while others are made by human beings .

Some changes are desirable to us but some changes are not desirable .

Types of changes

slow and fast changes .

Reversible and irreversible .

Slow changes

Changes which take place over a long period of time {hours , days , month , year}are known as slow changes .

Examples :

Growth of nail and hair .

Changes of seasons .

germination of seeds .

Fast changes

Changes which take place within a short period of time {second or minutes } are known as fast changes .

Examples :

Bursting of balloon .

Breaking of glass .

Bursting of fire crackers .

Bursting of paper .

Reversible changes

changes which can be reversed {to back the original state} are known as reversible changes .

Example :

Touch me not plant {responding to touch}.

Stretching of rubber band .

melting of ice .