Page 30 - ICSE Chemistry 8

ice cube when kept in open, changes into water. Similarly, when salt is added to water, it becomes salty.
Some other changes that take place in our surroundings include:
• Day changing into night • Changing of seasons
• Diges on of food • A baby growing into an adult

• Curdling of milk • Rus ng of iron objects
• Burning of fuels • Cooking of food

• Fermenta on • Ripening of fruits
• Clo ng of blood • A seedling growing into a plant

day and night burning of wood rusted iron object

baby and adult seedling growing into a plant melting of butter

Fig. 2.1: Changes around us

CLASSIFICATION OF CHANGES

Thinking Fountain
There are diff erent type of changes observed in nature. Some changes
Why is ripening of mango
result in change in shape, colour, size and posi on of a substance while
considered as irreversible
some result in a change in state altogether. Some are easy to spot while change? Is this change
some are diffi cult for us to no ce. Some are fast that take no me at all also desirable?
while some are slow and take years to happen.
Changes that occur around us can be classifi ed into diff erent categories.

These changes can be classifi ed as follows.
• Reversible and irreversible changes • Periodic and non-periodic changes

• Desirable and undesirable changes • Slow and fast changes
• Natural and man-made changes • Physical and chemical changes

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