Some notes on Oxygen cycle.

1. Oxygen:

2.  Is a chemical element with symbol O and
atomic number 8.
Tasteless gas.
Has no smell nor color.
Comprises 22% of the air.
Supports combustion.

3.  Is the biogeochemical cycle that describes
the movement of oxygen with its three
main reservoirs :
1. Atmosphere
2. Biosphere
3. Lithosphere

5. NB : Failure in the oxygen cycle within the
hydrosphere can result in the development
of Hypoxic zones.
Hypoxic zones- This is a condition caused
by excessive nutrient pollution from human
activities coupled with other factors which
in turn deplete or lowers the oxygen level
required by marine life.

7. Photosynthesis :
 Is a process used by plants and other organisms to
convert light energy into chemical energy that can
be later released to fuel the organisms activities.
 This chemical energy is stored in carbohydrate
molecules such as sugars which are synthesized
from carbon dioxide and water.
 Photosynthesis is derived from a Greek word Phõs
-“light” and Synthesis– “putting together”.
 Most plants, Algae and Cynobacteria perform
photosynthesis and they are referred to as
Autotrophs.
 Photosynthesis is responsible for the modern
earth’s atmosphere and life on earth.

8. 6CO2 + 6H2O + Energy
C6H12O6 + 6O2

9. Used :
To make acids (sulfuric, nitric acid) and
other compounds.
For boosting reaction rates and oxidation
of unwanted compounds.
 In medicine and healthcare institutions.
To generate energy.
For destroying rocks in mining.

10. Soil:
This are the air spaces present in the soil.
This are the air spaces present in the soil..
 Its composition is 20%.

11. Water :
Oxygen in water is known as dissolved
oxygen .
Oxygen enters the water from the
atmosphere as it dissolves and mixes into
the water surfaces.
Oxygen uptake rate (O.U.R.) is the rate at
which oxygen is consumed by living
organisms in the water.

12.  It appears as water bubbles.

13. NB: Question me after the class please!!!!
Conserve as much as you can!!!

14. Paulus N. Nakashole
16 March 2014