Khairul has conducted an investigation to study the relationship between animals X, Y and Z. They are put in a cage that has a pot of green plant and a bowl of water. The investigation was conducted for 5 days. The results are recorded in the Table.
1. Substances are classified as acidic, alkaline or neutral.
COLOUR OF LITMUS PAPER
1. We can use wet litmus paper to decide whether a substance is acidic,
alkaline or neutral.
2. Blue litmus paper is used to test for acidic substances.
3. Red litmus paper is used to test for alkaline substances.
4. Litmus must be damp.
5. Dry litmus does not change colour.
|
Substance
|
Effect on
|
|
|
Blue litmus paper
|
Red litmus paper
|
|
|
Acidic
|
Turns red
|
Does not change colour
|
|
Alkaline
|
Does not change colour
|
Turns blue
|
|
Neutral
|
Does not change colour
|
Does not change colour
|
ACIDIC SUBSTANCES
1. Corrosive when concentrated.
 |
| Vinegar |
|
| Yoghurt |
 |
| Lemon |
 |
| Pineapple |
|
| Tamarin |
ALKALINE SUBSTANCES
 |
| Bitter gourd |
|
| Baking powder |
|
| Toothpaste |
|
| Detergent |
|
| Soap |
|
| Shampoo |
|
| Milk of magnesia |
NEUTRAL SUBSTANCES
1. Tasteless, sweet and salty.
|
| Water |
|
| Salt |
|
| Sugar |
|
| Honey |
|
| Cooking oil |
NOTES
1. Acidic food tastes sour, alkaline food tastes bitter and neutral food does
not taste sour or bitter.
2. Red cabbage juice as an indicator. It turns red when acidic, purple when
neutral and greenish-yellow when alkaline.
IMPORTANCE
KEPENTINGAN
1. Water is important to all living things.
Air adalah penting kepada semua hidupan.
(a) We use water in our daily lives for drinking, washing and bathing.
Kita menggunakan air dalam kehidupan seharian untuk minum, mencuci,
dan mandi.
(b) Water also is used as a raw material in the food industry.
Air juga digunakan sebagai bahan mentah dalam industri makanan.
(c) Water is home to many living things.
Air adalah tempat tinggal bagi pelbagai hidupan.
EXAMPLES
CONTOH
1. All living things get their water supplies from various water resources.
Semua hidupan mendapatkan bekalan air daripada pelbagai sumber air.
2. Examples of water resources are rivers, ponds, lakes and oceans.
Contoh-contoh sumber air adalah sungai, kolam, tasik, dan lautan.
|
|||
| Sea (Laut) |
|
| Rivers (Sungai) |
|
| Springs (Anak sungai) |
|
| Lakes (Tasik) |
|
| Ponds (Kolam) |
|
| Wells (Perigi) |
HUMAN ACTIVITIES THAT AFFECT WATER RESOURCES
KESAN AKTIVITI MANUSIA TERHADAP SUMBER AIR
WATER POLLUTANTS
PENCEMARAN AIR
1. Domestic waste
Bahan buangan domestik
(a) Eventually reaches the natural water source.
Akhirnya sampai ke sumber air (sungai).
2. Industrial waste
Bahan buangan industri
(a) Toxic waste from factories poisons aquatic life in rivers and sea.
Bahan toksik dari kilang meracun hidupan akuatik di sungai dan laut.
3. Agricultural activities
Aktiviti pertanian
(a) Fertilisers and pesticides leach into water sources.
Baja dan racun serangga teresap ke sumber air.
4. Mining activities
Aktiviti perlombongan
(a) Displaced soil washed into water resources, contaminated with heavy
metals.
Tanah dibawa ke sumber air dan dicemari oleh logam berat yang toksik.
5. Oil spoilage
Tumpahan minyak
(a) Oil layer kill sea animals and ruin beaches.
Lapisan minyak membunuh hidupan laut dan merosakkan pantai.
6. As a result of human activities, water resources can become polluted.
Akibat aktiviti manusia, sumber air boleh tercemar.
7. Make water dirty, smelly, contains bacteria, contains toxic and harmful if
consumed.
Menjadikan air kotor, berbau, mengandungi bakteria, mengandungi toksik
dan memudaratkan jika diminum.
8. Polluted water contains harmful substances and bacteria that affect us and
other living things.
Air yang tercemar mengandungi bahan berbahaya dan bakteria yang boleh
menjejaskan kita dan hidupan lain.
KEEPING WATER SOURCES CLEAN
MENJAGA KEBERSIHAN SUMBER AIR
1. The ways to keep the water resources clean:
Langkah-langkah untuk memastikan kebersihan sumber air:
(a) Do not throw rubbish or toxic waste into the rivers, lakes or sea.
Jangan membuang sampah atau sisa toksik ke dalam laut, sungai atau
tasik.
(b) Build factories far away from the water resources.
Bina kilang-kilang jauh dari sumber air.
(c) Treat sewage from houses, factories and agricultural land before
releasing it into the seas or rivers.
Rawat kumbahan dari rumah, kilang, dan kawasan pertanian sebelum
melepaskannya ke laut atau sungai.
(d) Promote public awarness on the importance of water resources through
campaingn and the media.
Menggalakkan kesedaran masyarakat tentang kepentingan sumber air
melalui kempen dan media.
(e) Control the use of fertilizers and pesticides in agricultural land.
Kawal penggunaan baja dan racun perosak di kawasan pertanian.
(f) Use natural or organic fertilizer not chemical fertilisers.
Menggunakan baja asli atau baja organik bukan baja kimia.
(g) Recycle materials
Kitar semula bahan
(h) Conserve water and use less.
Memulihara air dan kurangkan penggunaan.
(i) Report to authority on dumping rubbish activities into water sources.
Laporkan kepada pihak berkuasa tentang pembuangan sampah ke sumber
air.
|
||||
| Polluted river (Sungai yang tercemar) |
MATTER
BAHAN
1. Anything that has mass.
Apa-apa sahaja yang mempunyai jisim.
2. Take up space.
Mengambil ruang.
3 STATES OF MATTER
3 KEADAAN BAHAN
1. Matter can exist in three states – solid, liquid and gas.
Bahan boleh wujud dalam tiga keadaan – pepejal, cecair dan gas.
SOLID
PEPEJAL
| Metals Logam |
| Plactic Plastik |
| Wood Kayu |
| Rock Batu |
| Clay Tanah liat |
| Concrete Konkrit |
| Rubber Getah |
| Water Air |
| Milk Susu |
| Petrol Petrol |
| Latex Susu getah |
| Honey Madu |
| Cooking oil Minyak masak |
| Shampoo Syampu |
| Tomato sauce Sos tomato |
| Soy sauce Kicap |
| Air Udara |
| Steam Wap |
| Oxygen Oksigen |
| Hydrogen Hidrogen |
| Carbon dioxide Karbon dioksida |
| Smoke Asap |
Pepejal, cecair dan gas mempunyai sifat-sifat yang berbeza.
2. Solid
Pepejal
(a) A solid has mass.
Pepejal mempunyai jisim.
(b) A solid has a fixed volume.
Pepejal mempunyai isi padu yang tetap.
(c) A solid has a fixed shape.
Pepejal mempunyai bentuk yang tetap.
(d) A solid cannot be compressed.
Pepejal tidak boleh dimampatkan.
3. Liquids
Cecair
(a) A liquid has mass.
Cecair mempunyai jisim.
(b) A liquid has a fixed volume.
Cecair mempunyai isi padu yang tetap.
(c) A liquid does not have a fixed shape but takes the shape of the container.
Cecair tidak mempunyai bentuk tetap tetapi mengambil bentuk bekas.
(d) Can flow. Different liquids have different flow rate.
Boleh mengalir. Cecair berlainan mempunyai kadar aliran yang berlainan.
(i) Water > Cooking oil > Shampoo > Tomato sauce
Air > Minyak masak > Syampu > Sos tomato
(e) A liquid cannot be compressed.
Cecair tidak boleh dimampatkan.
4. Gas
Gas
(a) A gas has mass.
Gas mempunyai jisim.
(b) A gas does not have a fixed volume but it occupies space.
Gas tidak mempunyai isi padu yang tetap tetapi gas memenuhi ruang.
(c) A gas does not have fixed shape but takes the shape of container.
Gas tidak mempunyai bentuk tetap tetapi mengambil bentuk bekas.
(d) A gas can be compressed.
Gas boleh dimampatkan.
|
Temperature of water (°C)
Suhu air (°C)
|
70
|
75
|
80
|
85
|
90
|
|
Time taken for the ping-pong ball to become round (seconds)
Masa yang diambil untuk bola ping-pong menjadi bulat (saat)
|
64
|
58
|
52
|
46
|
40
|
EFFECTS OF HEAT ON MATTER
KESAN HABA KE ATAS BAHAN
(1) Matter expands when heated.
Bahan mengembang apabila dipanaskan.
(a) Volumes increase
Isipadu bertambah
(b) Becomes bigger
Menjadi besar
(2) Matter contracts when cooled.
Bahan mengecut apabila disejukkan.
(a) Volumes decrease
Isipadu berkurang
(b) Becomes smaller
Menjadi kecil
APPLICATIONS OF EXPANSION AND CONTRACTION
APLIKASI PENGEMBANGAN DAN PENGECUTAN BAHAN
(1) The principle of expansion and contraction is applied in everyday life.
Prinsip pengembangan dan pengecutan diaplikasikan dalam kehidupan harian.
| Railway tracks are laid with gaps between them to allow for expansion during hot weather. Landasan kereta api dibina dengan ruang-ruang di antaranya untuk membolehkan pengembangan semasa cuaca panas. |
| Gaps are left between concrete slabs on pavements to allow for expansion on hot days. Ruang-ruang dibuat di antara kepingan konkrit pada laluan pejalan kaki untuk membolehkan pengembangan pada hari panas. |
| Electric cables are installed so that they sag to prevent them from snapping when they contract during cold weather. Kabel elektrik dipasang secara melendut untuk mengelakkan kabel daripada putus apabila mengecut semasa cuaca sejuk. |
| One end of a steel bridge is mounted on rollers to allow for expansion in hot weather. Salah satu hujung jambatan keluli diletakkan di atas penggolek untuk membolehkan pengambangan semasa cuaca panas. |
CHANGES IN STATES OF MATTER
PERUBAHAN KEADAAN BAHAN
Water can exist in three states – solid, liquid and gas.
Air boleh wujud dalam tiga keadaan – pepejal, cecair dan gas.
When water is heated or cooled, it will change into another state.
Apabila air dipanaskan atau disejukkan, ia akan berubah kepada bentuk yang lain.
The change of state of water takes place through certain process such as:
Perubahan keadaan air berlaku melalui proses-proses tertentu seperti:
(a) Melting
Peleburan
(b) Freezing
Pembekuan
(c) Condensation
Kondensasi
(d) Boiling
Pendidihan
(e) Evaporation
Penyejatan
MELTING
PELEBURAN
Ice melts into water (Solid –> Liquid) at temperature higher than melting point (0 °C).
Ais melebur menjadi air (Pepejal –> Cecair) pada suhu di atas takat lebur (0 °C).
FREEZING
PEMBEKUAN
Water freeze into ice (Liquid –> Solid) at temperature below than freezing point (0 °C).
Air membeku menjadi ice (Cecair –> Pepejal) pada suhu bawah takat beku (0 °C).
CONDENSATION
KONDENSASI
Steam condenses into water when touches a cold surface (Gas –> Liquid).
Wap terkondensasi menjadi air apabila ia disejukkan (Wap –> Cecair).
BOILING
PENDIDIHAN
Water boils into steam (Liquid –> Gas) at boiling point (100 °C). Boiling occurs throughout the liquid.
Air mendidih kepada wap (Cecair –> Gas) pada takat didih (100 °C). Pendidihan berlaku di keseluruhan cecair.
EVAPORATION
PENYEJATAN
Evaporation (liquid –> gas) only occurs at the surface of water at any temperature.
Penyejatan (cecair –> gas) hanya berlaku pada permukaan air pada sebarang suhu.
FACTORS AFFECTING EVAPORATION RATE
FAKTOR YANG MEMPENGARUHI KADAR PENYEJATAN
The rate of evaporation of water increases when surface area is larger, the temperature of the surroundings is higher and there is wind.
Kadar penyejatan air meningkat apabila luas permukaan adalah besar, suhu persekitaran tinggi, dan adanya angin.
A water is heated for 6 minutes. Then, the water is left to cool.
Air dipanaskan selama 6 minit. Kemudian, air dibiarkan menyejuk.
Table shows the temperature of the water taken every 2 minutes.
Jadual menunjukkan suhu air yang dicatatkan setiap 2 minit.
|
Time (minutes)
Masa (minit)
|
0
|
2
|
4
|
6
|
8
|
10
|
12
|
|
Temperature of water (°C)
Suhu air (°C)
|
30
|
42
|
54
|
66
|
60
|
54
|
48
|
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