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On a Sunday morning, Paheli’s friend visited her home. She wanted to see some flowering plants in the nearby garden. Both of them went to the garden. While returning from the garden they also observed some flowering plants on the roadside. But to their surprise, they found that the leaves and flowers of these roadside plants were comparatively very dull. Can you help them to know why?

Paheli and her friend observed plants will dull leaves and flowers because of the air quality present in the open area. Air is polluted on... View Article

Paheli kept some water in a beaker for heating. She observed that tiny bubbles appeared before the water started to boil. She boiled the water for about 5 minutes and filled it in a bottle up to the brim and kept the bottle airtight till it cooled down to room temperature. (a) Why did the tiny bubbles appear? (b) Do you think tiny bubbles will appear on heating the water taken out from the bottle? Justify your answer.

Paheli had boiled out the complete water that means all the air from the water escaped out, so on boiling the boiled cooled water will not make... View Article

A list of words is given in a box. Use appropriate words to fill up the blanks in the following statements. [Air, oxygen, wind, water vapour, mixture, combination, direction, road, bottles, cylinders] (a) The ______ makes the windmill rotate. (b) Air is a ______ of some gases. (c) A weathercock shows the in which the air is moving at that place. (d) Mountaineers carry oxygen ___ with them while climbing high mountains.

(a) Wind Wind can be described as the movement of air from the high-pressure area to the low-pressure area. There are many types of wind such as... View Article

State whether the following statements are true or false. If false, correct them. (a) Plants consume oxygen for respiration. (b) Plants produce oxygen during the process of making their own food. (c) Air helps in the movements of sailing yachts and gliders but plays no role in the flight of birds and aeroplanes. (d) Air does not occupy any space.

(a) True During respiration, in different plant parts, significantly less exchange of gas takes place. Hence, each part nourishes and fulfils its... View Article

Boojho took an empty plastic bottle, turned it upside down and dipped its open mouth into a bucket filled with water. He then tilted the bottle slightly and made the following observations. (i) Bubbles of air came out from the bottle. (ii) Some water entered the bottle. (iii) Nitrogen gas came out in the form of bubbles and oxygen got dissolved in water. (iv) No bubbles formed, only water entered the bottle. Which observations is/are correct? (a) (i) and (ii) (b) (iv) only (c) (iii) and (iv) (d) (i) only

(i) Bubbles of air came out from the bottle.  (ii) Some water entered the bottle. When the bottle was tilted then the bubbles of air come out... View Article