Why methane gas is lighter than air and how does it affect the ozone layer?
(Asked Shreyanka, Class VII C, KV Bidar)
Answer: The density, i.e; the mass per unit volume of methane is less than that of air (which is a mixture of many gases) Methane react with ozone converting it into oxygen and thus the ultraviolet absorbing power is lost. More percentage of UV rays will reach the earth. Normally about 50% of the UV rays reaching the upper atmosphere are absorbed or reflected back.
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