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1. MATTER IN OUR SURROUNDINGS
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निम्नलिखित अवलोकनो हेतु कारण लिखें
$(a)$ नैफ़्थलीन को रखा रहने देने पर यह समय के साथ कुछ भी ठोस पदार्थ छोड़े बिना अदृश्य हो जाती है।
$(b)$ हमें इत्र की गंध बहुत दूर बैठे हुए भी पहुँच जाती है।
Option A
Option B
Option C
Option D
Solution
$(a)$ Naphthalene is a substance which directly changes from solid to gas on heating by the process of sublimation. So, the naphthalene balls disappear with time as they sublime due to heat of surroundings.
$(b)$ The smell (aroma) of perfume reaches several meters away due to the fast diffusion of the gaseous perfume particles through the air.
Standard 9
Science
