This is PPT was presented by Mr. Girishwar of 9th std, JNV Lepakshi, to the INOVIT-2015 organised by Vellore Institute of Technology, Vellore, Tamilnadu on 24-25th Jan 2015.

1. INOVIT-2015
SOUTH INDIA LEVEL SCIENCE CONTEST FOR
SCHOOL CHILDREN
Venue: VIT University, Vellore-632 014,
Tamil Nadu
24-25, January 2015
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2. PARTICIPATOR DETAILS
NAME : M.GIREESHWAR
CLASS : IX
THEME : OZONE LAYER
INSTITUTION : JAWAHAR NAVODAYA
VIDYALAYA,
LEPAKSHI,
ANANTAPUR (dist.)
ANDHRA PRADESH
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4. • Our green Earth is protecting us like a tree.
• Though Earth is giving everything, man was making it to be
destroyed.
• One of the big destruction making by man was destroying
the ozone layer.
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5. • On the earth, there are many atmospheric layers which protect us
always.
• Species are living in Troposphere with sufficient Oxygen (O2).
• Stratosphere is fully covered with Ozone gas(O3).
• Stratosphere is spread over 50kms in height and associated with
weather.
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7. • OZONE = (O3) (in chemistry)
• Ozone is basically formed in the Earths atmosphere (Stratosphere)
• Ozone is a mixture of small fraction of N2 and O2 gases.
• At near ground level, ozone is an air pollutant. Even at low
concentration, it is irritating to the respiratory system.
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8. • If ozone gas is on stratosphere, man will be protected from harmful Ultra
violet rays.
• Ozone protects us from many skin cancer and many harmful diseases.
• It also protects plants and marine life.
• Ozone is much more reactive than O2.
• It occurs naturally in small amounts in the Earth's upper atmosphere.
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10. •Ozone is formed from atmospheric oxygen in the presence of sunlight. Ozone layer
protects the earth’s surface from an excessive concentration of UV radiations.
•Experiments have shown that Nitrogen Oxide combines very rapidly with Ozone Gas and
there is, thus, the possibility that Nitrogen Oxides emitted from the exhaust systems of
supersonic jet aeroplanes might be slowly depleting the concentration of the Ozone layer in
the upper atmosphere.
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11. Ozone layer started to become thinner in the width and made holes which
are known as ozone holes.
Ozone holes are caused by ODS (Ozone depleting substances).
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12. ODS are chemicals that potentially deplete the ozone layer.
ODS contain chlorine and bromine atoms.
ODS are released from refrigerators, pesticides, jets, rockets, etc.
E.g. For ODS are chlorofluorocarbons (CFCs), carbon tetrachloride.
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15. • When the ozone layer gets holes, they can’t stop Uvradiations and
infra-red rays from sun.
• This results in falling of UV rays directly on human which inturn
results in damage of human DNA, skin cancer and eye cataracts.
• Many trees and aquatic life will be destroyed.
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17. • For protecting us and our green earth, we have to reduce the
usage of ODS, CFCs, etc. The following steps are to be taken.
1) We have to plant trees.
2) Burning of plastic should be banned.
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18. 1) We should ban/reduce the usage of Montreal protocol.
2) We have to use non-polluting vehicles.
3) We have to use eco-friendly house hold cleaning products.
4) We have to avoid usage of pesticides.
5) We have to ban the usage of green house gases like methane, CO2, nitrous
oxide.
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21. • Ozone plays a key role in the temperature structure of the earth’s
atmosphere.
• Many experimental studies of plants and animals and clinical studies of
humans have shown the harmful effects of excessive exposure to UV-B
radiation.
• Ozone reacts strongly with other molecules.
• Chlorofluorocarbons are released from spray cans, refrigerants, electronic
cleaning agents and foam.
• CFCs had hailed as the “wonder chemicals”.
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