2 條 科學 的問題 ( 英文 ) 急急急 !!!

1.
The ozone layer is in the stratosphere, which is a layer of atmosphere 20-50 km above the Earth’s surface. In the stratosphere, the amount of ozone is kept nearly constant, as ozone is constantly created and destroyed.

There is a series of reactions that occurs in the zone layer. The most important reaction is the decomposition of ozone by absorption of a wide range of ultraviolet light of wavelength 215-295 nm.
O3 → O2 + O (absorbing uv light)

The ozone layer in the stratosphere filters out 99% of dangerous ultraviolet light from the sun. A thinning of the ozone layer may lead to an increase in the incidence of skin cancer and eye cataract, and a decrease in yield of crops.

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2.
The Cl atoms (i.e. Cl free radicals) destroy ozone via a sequence of the following reactions :
Cl + O3 → ClO + O2 ...... (*)
ClO + O → Cl + O2 ...... (**)

The above reactions speed up the destruction rate of ozone. This is because ozone is fast destroyed by Cl atoms in reaction (*), and one Cl atom can effectively destroy many ozone molecules as the Cl consumed in reaction (*) is regenerated in reaction (**).

Consequently, this causes thinning of ozone layer.

1) because O3 can trap UV light to prevent penetration of harmful light with high energy.

2) As Cl2(g) can react with O3(g),
the amount of O3 can be reduced by Cl2(g).
If too much Cl2 present in the atmosphere,
The ozone layer in the atmosphere will then be damaged.