A complete BIOLOGY SPM exam focus ,marking scheme included. Made BIOLOGY learning easierFull description
A complete BIOLOGY SPM exam focus ,marking scheme included. Made BIOLOGY learning easierFull description
SCIENCE Form 1
UNIT 5 .3 ,5.4 The Air Around Us yschow88@smkbpj(a)
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5.3
OXYGEN IS NEEDED FOR RESPIRATION
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What is respiration? The chemical process in which energy is released from the breaking down of food is called respiration. •
ere oes respiration take place? Respiration occur in the body cells. yschow88@smkbpj(a)
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How does respiration take part? • Resp Respir irat atio ion n requ requir ires es oxyg oxygen en.. Oxyg Oxygen en oxidises the glucose in the body cells to release energy. vapour are the waste products in respiration: Gucose
Oxygen
Energy
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Carbon dioxide
Water vapour
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Experiment to find the difference in oxygen content between inhaled and exhaled air.
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What gas is needed for respiration?
• Responding- Co Cont nten ents ts of air air in th the e bo boililin ing g ttub ube e • Constant-
The presence of living organisms
• Manipulated- The Theyschow88@smkbpj(a) positi position on of me merc rcur ury y thread thread
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Result • The me mercur rcury y thr thre ead of A and and B moves towards the boiling tubes. • Whil While e the the me merc rcur ury y thr threa ead d at at boi boililing ng tu tube be C . Conclusion: Conclusion: Oxygen is needed by animals and plants during respiration. yschow88@smkbpj(a)
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Do organisms release carbon dioxide during respiration?
• Responding - Con Conten tents ts of air in the boiling boiling tube tube • Constant - The prese presence nce of of livin living g organis organisms ms • Manipulated -The colour change carbonate indicator (bicarbonate indicator) yschow88@smkbpj(a)
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Result The hydrogen carbonate indicator in tube X and Y change from red to yellow yellow,, while the hydrogen carbonate indicator in tubes . Conclusion Organisms release carbon dioxide during respiration. yschow88@smkbpj(a)
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Experiment to show the products of respiration
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Check point
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Summary so far :
Humans require chemical energy to carry out life processes. This energy is obtained when sugars from digested food are broken down during respiration.
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Demand for energy
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5.4
OXYGEN IS NEEDED FOR COMBUSTION
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Combustion Combustion is the burning of substances in air. air. The substance (fuel), reacts rapidly with ox en to roduce heat and li ht. Combustion is a chemical process because during this process new substances are formed. yschow88@smkbpj(a)
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Conditions for combustion Combustion can only occur when these three conditions are satisfied, that is, the presence of: a. a substance that can burn, or a fuel (2 types) ii. Hydrocarbon b. Oxygen c. Heat to warm the fuel until it reaches ignition temperature. yschow88@smkbpj(a)
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The combustion of carbons The combustion of carbons like firewood, charcoal and coal produces carbon dioxide and energy in the form of heat and light Carbon + oxygen Carbon dioxide + energy yschow88@smkbpj(a)
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The combustion of hydrocarbons The combustion of hydrocarbons which are compounds of hydrogen and carbon, produces carbon dioxide, water and energy in the form of heat and light. Examples of hydrocarbons: hydrocarbons : 1. Kerosene 2. Petrol 3. Diesel 4. wax.
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The combustion of hydrocarbons
Hydrocarbon + oxygen
Carbon dioxide + Water + energy
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5.5
AIR POLLUTION
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Substances that Pollute the Air • Air Air pol pollu luti tion on occu occurs rs wh when en air air con conta tain ins s pollutants.. pollutants •
o utants are arm u su stances t at are released into the environment. released into the environment.
• Air Air pol pollu luti tion on is th the e res resul ultt of of the the acts acts of human. yschow88@smkbpj(a)
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Thinning of the ozone layer • Chlorof hlorofluoroc luorocarbon (CFC) form aerosol cans, refrigerators, air conditioners and electronic factories. • Destroys th the oz ozone la layer in Earth's atmosphere • U Ultraviolet ltraviolet light light causes cataracts and skin cancer and skin cancer yschow88@smkbpj(a)
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Acid Rain • Nitr Nitrog ogen en di dioxi oxide, de, nit nitro roge gen n mono monoxid xide e and and sul sulph phur ur dioxide dissolve in rain drops to form acid rain.
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Acid Rain
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5.6
THE IMPORTANCE OF KEEPING THE AIR CLEAN yschow88@smkbpj(a)
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Nowadays Nowada ys many many o off our our surrou surroundi nding ng peo people ples sa are re live live in suffer suffering ing of health problems such as lung cancer, asthma, skin disease, impaired of eye-sight and etc
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Acci Accide dent nts s and and brea breath th prob proble lems ms incr increa ease ses s du due e to to air air po pollllut utio ion n such such as haze
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Ways to ke keep the air cl clean: i. Plant more trees at surrounding . Iii. Encourage habit of recycling recycling by discarding materials made made from wood, plastic, glasses and tin
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Ways to keep the air clean iv. iv. Prac Practi tice ce carcar-po pool olin ing g or pref prefer er wa walk lkin ing g of distance instead of driving
shor shortt
v. Practice using solar energy. v.
o n o t s mo e
vii. Avoid open burning of waste products, such as rubbish and plastics
