Fast and Slow Changes

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Fast and Slow Changes: Overview

This topic covers concepts such as Preventive Measures of Rusting of Iron, Types of Changes around Us, Slow Changes, and Fast Changes.

Important Questions on Fast and Slow Changes

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Choose the right word and fill in the blank provided below.

When we heat water in a pan, it begins to boil after some time. If we continue to heat further, the quantity of water in the pan will _____. (decrease, increase)

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Give one word for the following:  

Melting is the reverse of this process: 

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What happens to naphthalene balls kept in an almirah after a few days? Why?

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Write two heat-absorbing changes.

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Write the difference between physical and chemical changes with examples.

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How many types of changes are there?

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There is some reason behind every change.

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Which of the following is a reversible change-

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In physical change -

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Observe the following pictures. Write for a slow change and for a fast change.

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Give some examples of fast and slow changes that occur in your surroundings.

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Changes that may take place on mixing two substances are always reversible.

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Tell the difference between physical and chemical changes. 

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Describe how heat can cause substances to change.

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Differentiate between physical and chemical changes with the help of examples.

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List out common changes in surroundings.

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Why do changes occur?

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Give two examples of changes which are exothermic.

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The process of conversion of water into water vapour is called condensation.

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Why are metal articles electroplated?