Question

Everyday you come across many changes in your surroundings. These changes may involve one

or more substances. Ex: your mother may ask you to dissolve sugar in water to make a cold

drink. Making a sugar solution is a change; broadly these changes are of two kinds, Physical and

Chemical. Physical changes are changes in the physical properties of substances. No new

substances are formed in these changes. In Chemical changes new substances are produced.

Rusting of iron is an example of chemical change. For rusting, the presence of both oxygen and

water is essential. To prevent rusting one simple way is to apply a coat of paint or grease.

Another way is to deposit a layer of a metal like chromium or zinc on iron, the process of

depositing a layer of zinc on iron is called galvanization.

DAY – III

1. Choose the correct option:

a) Which of the following is a chemical change?

i) melting of ice ii) rusting of iron iii) dissolving of salt in water

b) Chemical changes are characterized by

i) formation of new substances ii) reversible iii) release of energy​

Answer 1

Answer:

a)answer dissolving of salt in water

b)formation of new substances