Question
Why do stars twinkle on a clear night?
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Answer
The light coming from a star undergoes atmospheric refraction due to varying optical densities of air at various altitudes. The continuously changing atmosphere refracts the light from the star by different amounts from one moment to the next. Thus, the star-light reaching our eyes increases and decreases continuously and the star appears to twinkle.
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$NH _{3(g)}+ HCl _{( g )} \rightarrow NH _4 Cl _{( s )}$ - (1)
$2 Mg + O _2 \rightarrow 2 MgO$ - (2)
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(ii) What is the number of molecules of reactants taking part in the above reactions?
(iii) How many products are formed in each of the above reaction?
→(i) What is the number of reactants in the following reactions.
$NH _{3(g)}+ HCl _{( g )} \rightarrow NH _4 Cl _{( s )}$ - (1)
$2 Mg + O _2 \rightarrow 2 MgO$ - (2)
$CaO + H _2 O \rightarrow Ca ( OH )_2+$ Heat - (3)
(ii) What is the number of molecules of reactants taking part in the above reactions?
(iii) How many products are formed in each of the above reaction?
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