 |
| Composition of Air |
Properties of oxygen : - slighty soluble in water ; not soluble in sodium hydroxide ; relights glowing splinter ; has no effect on moist litmus papers.
 |
| Oxygen relights glowing splinter |
Properties of carbon dioxide : Slighty soluble in water ; Very soluble in sodiem hyroxide ; lime water turns cloudy ; change moist blue litmus paper to red.
 |
| Carbon dioxide turns lime water cloudy |
The content of oxygen in exhaled air is lower than inhaled air. Human beings breathe through the respiratory system.
The respiratory system involves the process of oxidation of food in living cells.
During respiration, oxygen is absorbed into the cells, while carbon dioxide will enter the alveolus to be excreted.
Combustion takes place when a substance combines with oxygen chemically to release heat and light energy.
Combustion of carbon produces carbon dioxide, light and heat energy. Combustion of hydrocarbon produces carbon dioxide, water, heat and light energy.
Green plants carry out photosynthesis to manufacture food.
 |
| Photosynthesis |
Air pollution occurs when the air is made dirty by air pollutants such as smoke, dust, carbon monoxide, sulphur dioxide, nitogen dioxide, and residues of pesticides.
The causes of air pollution include motor vehicles, factories, burning of rubbish, and widespread use of pesticides.
Air pollution can cause acid rain, increase in Earth's temperature (greenhouse effect) and thining of the ozone layer, and affect the health of organisms.
 |
Air Pollution |
(Source : from revision book : Eastview New Version PMR Science )
For more information and notes, you can assess to the link below :
The Air Around Us (Part 2) -this one is more to properties of combustion and respiration and also related experiment in which student should know.
Students, don;t forget to do exercise on any revision book so that you can master the skills and knowledge faster!
You are welcome to drop any comment here ^^
ReplyDeleteThk #^__^
ReplyDeleteThanks 4 the information! >_<
ReplyDelete