Oxygen is a colorless, odorless gas essential for respiration in humans and animals and plays a crucial role in decomposition and aquatic life. Discovered by Carl Wilhelm Scheele in 1772, oxygen composes approximately 21% of the atmosphere and is involved in oxidation reactions. It is produced through processes like photosynthesis and is found in the biosphere, atmosphere, and lithosphere.

2. UMER FAROOQ.
ANUM AJMAL .
MISBAH SADIQ.
NOMAN HAFEEZ.
2

3. Energy
released
OXYGEN

4.  Is the colourless , odourless and
tasteless gas.
 Oxidation – it is the process of uniting
or of causing a substance to unite with
the oxygen.

5.  Carl Wilhelm Schele – a Swedish
chemist who discovered oxygen for the
first time in 1772.

6. 6

7.  Humans need it to breathe.
 Needed for decomposition of organic
waste.
 Water can dissolve oxygen and it is
this dissolved oxygen that supports
aquatic life.

8. 8

9. 9

11. 11

12. 12

13.  The east’s atmosphere consists of 21%
oxygen
 The earth’s lithosphere consists of
99.5% oxygen
 The earth’s hydrosphere consists of
46.60% oxygen.
 The earth’s biosphere consists of
0.01% oxygen.

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17. 17

18. 18

19. Respiration
Photosynthesis

21. 21

22. 22

23.  Name-oxygen
 Symbol-O
 Atomic no.-8
 Uses-for oxidation reactions for the
respiration for the respiratory function
of humans, animals, plant, some types
of bacteria e.tc.
 Sources- photolysis, photosynthesis.
 Reservoir-biosphere, atmosphere,
lithosphere.

26. QUESTION
SESSION?