Survival Of The Species ( Plants )

1. Different plants have their own ways to ensure the survival of their species.

2. Plants needs to disperse their seeds or fruits to ensure the survival of their species.

3. Plant that disperse seeds and fruits by water.

Coconut

Lotus

Pong-pong

    The seeds or fruits of the plants that grow at river side or sea side have air space and are light.


4. Plants that disperse seeds and fruits by wind.

Angsana

Lalang

  The seeds or fruits of the plants that are disperse by wind have wing-like structure, dry, have fine
  hairs and are small.

Papaya

5. Plants that disperse seeds and fruits by animals.

Rambutans

Durian

   The fruits of the plants are fleshy, brightly coloured and edible.
   The seeds are hard and cannot be eaten.
   So the animals throw the seeds to another places.

Grass

Love Grass

Mimosas

   The seeds or fruits of the plants have hooks, to stick on animals legs and bodies and dispersed to
   other places.


6. Plants that disperse seeds and fruits by explosive mechanism.

Balsam

Rubber tree

Pea

  When the fruits of these plants ripe, their skin will dry and become hard. Then the fruits explode and
  disperse their seeds.

Phases Of The Moon (Song)

PHASES OF THE MOON

1. Only the part of the moon that faces the Sun can be seen.

2. When the Moon revolves around Earth, the part of the Moon's surface that receives sunlight will 
    change.

3. That is why the shape of the Moon that we can see always changes.

4. The different shapes of the Moon are known as phases of the Moon.

5. The phases of the Moon consists of:

    (a) New moon

• The surface of the Moon that is not illuminated is facing Earth.
• The Moon cannot be seen from earth. 

New Moon

    (b) Crescent  
  

Crescent

    (c) Half moon ( First quarter )

• The surface of the Moon that is illuminated and facing Earth increases.
• The Moon looks bigger and rounder.     

Half moon (First quarter)

    (d) Gibbous

• The surface of the Moon that is illuminated and facing Earth increases.
• The Moon looks bigger and rounder.

Gibbous

    (e) full moon

• The whole surface of the Moon that receives sunlight faces Earth.
• The Moon looks big and round.

       

Full moon

    (f) Gibbous

Gibbous

    (g) Half Moon ( Last quarter )

• The surface of the Moon that is illuminated and facing Earth decreases.
• The Moon looks smaller.

Half Moon (Last quarter)

    (h) Crescent

Crescent

6. The Moon takes about 29.5 days to return to the same phase.

7. The Lunar Calendar is a calendar created based on the revolution of the Moon around Earth,
    following the phases of the Moon.

8. According at the Lunar Calendar, the Moon experiences full moon on the 15th of every month.

 

Measuring the temperature of the water

Question: What are the changes in the temperature of water when heat is gained and lost?

Aim: To study changes in temperature of water when heat is gained and lost.

Apparatus: Retort stand, matches, beaker, tripod stand, thermometer, bunsen burner, wire guaze and
                  water.

                                                                                                  
Procedure:
1.  Pour water into the beaker, measure the temperature of the water.

2. Heating the water three minutes, record the temperature of the water every one minute.

3. After three minutes, turn off the bunsen burner, record the temperature of the water until the sixth
    minute.

4. Record the observation in Table 1.

    Observation:
    

Stage	Before heating		During heating			After heating
Time (minutes)	0	1	2	3	4	5	6
Temperature	25	32	38	60	42	38	30

  
                                                                   Table 1

Discussion: What to keep the same in the experiment?

                    Volume of water used.

Conclusion: Temperature of water increases when heating the water, while temperature of water    
                    decreases when stop heating the water.

Thermometer

1. A thermometer is an instrument to measure temperature.

2. Units for temperature are : a) degrees  Celsius  ( °C )
                                                        b) degrees Fahrenheit  ( °F )


3. A thermometer consists of a narrow glass tube with a bulb at the tip.

Thermometer

4. The bulb is filled with mercury ( silver ) or alcohol ( red ).


5. Mercury will expand when heated.

6. The volume of mercury increases as the mercury expands.

7. This will cause the mercury level in the tube to rise.

8. Mercury will contract when cooled.

9. The volume of mercury decreases as the mercury contracts.

10.This will cause the mercury level in the tube to fall.

11.The rise and fall of mercury level shows the temperature reading of an object.

What food is acidic? What food is alkaline?

Aim: To investigate the properties of acidic, alkaline and neutral food.

Procedure: 1.Prepare food samples as below.

water

noodles

vitagen

bitter gourd

orange

                  2.Taste each of food samples, then record the taste of the food.

                  3.Use wet blue and red litmus paper to test the food samples.

                  4.Record the observation into table 1.


Observation:

Food sample	Taste	Red litmus paper	Blue litmus paper
Bitter gourd	Bitter	Red è blue	Blue è blue
Orange	Sour	Red è red	Blue è red
Noodles	Bitter	Red è blue	Blue è blue
Water	No taste	Red è red	Blue è blue
Vitagen	Sour	Red è red	Blue è red

                                                                        Table 1

Conclusion: 1. Acidic food tastes sour, changes blue litmus paper to red.


                    2. Alkaline food tastes bitter, changes the red litmus paper to blue.


                    3. Neutral food does not taste either sour or bitter, cannot change the colour of blue or red
                        litmus paper.

Chemical Properties Of Matter

ACIDIC, ALKALINE AND NEUTRAL

1. Different substances have different chemical properties.
2. Substances can be classified as having these properties:

•  acidic
• alkaline
• neutral

     3.  A substance can be tested to see if it is acidic, alkaline or neutral using a litmus paper.

   

Acidic Substances

1. An acidic substance has a sour taste.
2. It change blue litmus paper to red.
3. If the acidic substance is tested with a red litmus paper, no colour change will be seen.
4. A strong acidic is corrosive and can burn the skin.

orange

          



grapes 

pineapple

lemon

mango

apple cider vinegar

                  Figure 1: Acidic substances

Alkaline Substances

1. Alkaline substances taste bitter and feel 'soapy' to touch.
2. It change red litmus paper to blue.
3. If the alkaline substance is tested with a blue litmus paper, no colour change will be seen.
4. A strong alkaline is corrosive and can burn the skin.

detergent powder

bitter gourd

soap

body shampoo

toothpaste

Figure 2: Alkaline substances  

Neutral Substances

1. A neutral substance does not have an acidic or alkaline properties.
2. It will not change the colour of blue or red litmus paper.
3. If an acidic substance is mixed with an alkaline substance, a neutral substance is formed.

cocking oil

mineral water

sugar

rice

honey

bread

           

                                            

Figure 3: Neutral substances       

Experiment: Pendulum for measuring time

• Question: Are the swings of a pendulum uniform?
• Aim: To study the relationship between the length of the string and the period of the pendulum to swing 20 times.
• Apparatus: String, stopwatch, nut, scissors and retort stand.

Procedure:

1. Tie a 10 cm string onto the nut to become a pendulum.
2. Swing the pendulum and record the period for the pendulum to swing 20 times.
3. Repeat procedure 1 and 2 with 15 cm, 20 cm and 25 cm strings.
4. Record the observation.

Observation:

The length of the string (cm)                      10           15          20          25

The period for the pendulum
to swing 20 times (second)                         20           25          30          35


Discussion:

1. What is the trend of change for the period of the pendulum to make 20 swings?

          Increase uniformly

     2.  State two variables in the investigation.

          The length of the string used and the period of the pendulum to make 20 swings.

Conclusion: The longer the string, the longer the period for the pendulum to swing 20 times.