I think most of you will have no problem with this topic. The problem lies with the way you answer the questions during examination. Most of the time, the questions will give you some characteristics of living things and ask you to explain a) How you know that it is a living /non-living thing? or b) What is/ are the missing characteristics?
So, answer to the questions, DO NOT just 'throw out' all the characteristics. Read the questions to identify what are the characteristics, given and what are the missing ones.
Characteristics of Living Things:
1. They need air, water and food. Animals either hunt or look for food. Plants make their own food. Animals need oxygen for respiration. Plants need oxygen for respiration and carbon dioxide for photosynthesis.
2. They can reproduce. That's why you have the life cycle. They reproduce so as to ensure their own kind exist.
3. They can grow and die. Living things die due to a)lack of food and water b) eaten by others c)old age and d) diseases.
4. They can move by themselves. Animals move to look for shelter, food and get away from danger. Plants move their plants parts to get water and enough sunlight.
5. They respond to changes. Animals and plants move because they respond to changes. Remember, I tried to tickle Wesley and he tried to move away? The mimosa leaves close up when touched.
You must know how to spell all the words.
Some things may not display the above characteristics but are living things. Example, seeds (They do not move, but they will germinate and grow into plants.) and pupa (They will continue to develop into the adult stage.)
Saturday, October 13, 2007
Magnet (2007)
A magnet can attract objects made of steel, iron, nickel and cobalt.
The pull of a magnet is called magnetism. The objects that can be attracted are called magnetic objects.
A magnet cannot attract non-magnetic objects.
Only magnets can repel magnets. The only way to test if an object is a magnet, is when it repels.
Lodestones are natural black stones that attract iron materials.
The pull of magnets can pass through some non-magnetic objects such as wood, glass and water.
There are 2 poles on a magnet, regardless of the shape and size. A freely hanging magnet always stops in a north-south direction.
Like poles (N-N or S-S) repel each other.
Unlike poles (N-S or (S-N) attract each other.
Uses of magnets:
1. Separate magnetic substances from other materials.
2. In appliance and toys. Example, telephone and electric bells.
3. Telling direction. Compass.
4. Holding objects. Example, refrigerator, magnetic pencil case and the door stopper.
Ways to make temporary magnets:
1. Touch Method. When a paperclip is attracted to a magnet, the paperclip becomes a temporary magnet because it can attract other paperclips. Once the magnet is removed, the paperclip will lose its magnetism.
2. Stroking. Use a magnet to stroke a magnetic object eg. iron bar. Stroking must be done in one direction, from one end to the other end. To make a stronger temporary magnet through stroking, you can increase the number the strokes and also use a stronger magnet.
3. Electrical Method. Use batteries attached to a wire and coil the wire around the magnetic object. The magnetic object becomes a magnet only when the electricity is switched on. To make a stronger electromagnet, you can increase the current (use more batteries and use stronger batteries) and increase the number of coils around the magnetic object.
Ways to demagnetism a magnet: Hit, Heat and Hammer
The pull of a magnet is called magnetism. The objects that can be attracted are called magnetic objects.
A magnet cannot attract non-magnetic objects.
Only magnets can repel magnets. The only way to test if an object is a magnet, is when it repels.
Lodestones are natural black stones that attract iron materials.
The pull of magnets can pass through some non-magnetic objects such as wood, glass and water.
There are 2 poles on a magnet, regardless of the shape and size. A freely hanging magnet always stops in a north-south direction.
Like poles (N-N or S-S) repel each other.
Unlike poles (N-S or (S-N) attract each other.
Uses of magnets:
1. Separate magnetic substances from other materials.
2. In appliance and toys. Example, telephone and electric bells.
3. Telling direction. Compass.
4. Holding objects. Example, refrigerator, magnetic pencil case and the door stopper.
Ways to make temporary magnets:
1. Touch Method. When a paperclip is attracted to a magnet, the paperclip becomes a temporary magnet because it can attract other paperclips. Once the magnet is removed, the paperclip will lose its magnetism.
2. Stroking. Use a magnet to stroke a magnetic object eg. iron bar. Stroking must be done in one direction, from one end to the other end. To make a stronger temporary magnet through stroking, you can increase the number the strokes and also use a stronger magnet.
3. Electrical Method. Use batteries attached to a wire and coil the wire around the magnetic object. The magnetic object becomes a magnet only when the electricity is switched on. To make a stronger electromagnet, you can increase the current (use more batteries and use stronger batteries) and increase the number of coils around the magnetic object.
Ways to demagnetism a magnet: Hit, Heat and Hammer
Sunday, October 7, 2007
Our Senses (2007)
In case, you do not know... we have 5 senses. They are the sense of sight, smell, hearing, taste and touch. Many pupils like to mix them up with the sense organs. Sense organs are parts of our body, so our 5 sense organs are eyes, nose, ears, tongue and skin. I do not know why, but many pupils like to spell tongue wrongly. They also like to put mouth and their hands as sense organs. Please!! Other parts of your body can also feel, it is not just the hand!
Our senses enable us to observe and detect changes in our surrounding, so that we can take care of ourselves.
Skin. Our skin allows us to feel and know its properties. We know whether an object is hard or soft, warm or cold, sharp or blunt when we touch it. It also protects us. When we feel pain, we will withdraw our body from the object. Anyone of you will let me pinch you and you do not feel any pain??
Eyes. Our eyes enable us to observe properties of an object. We know the colours, shapes and sizes. They also help use to count, recognize things and look for things. People who are blind have to make use of other senses to make up for their disadvantage.
Ears. Our ears enable us to distinguish sounds. Sounds can be pleasant or unpleasant, loud or soft, high or low pitched. Our eyes also tells us where sounds come from. That's why we also try to get our friends to talk to us so that we can find their hiding place when we play hide-and-seek.
Nose. Our nose distinguish pleasant and unpleasant smells. It warns us about changes in the environment. Would you want to eat something that smells really bad? You will also know when Mummy has something that is overcooked from the smell.
Tongue. Our tongue enable use to distinguish the four types of taste; sweet, sour, salty and bitter. People who pierce their tongue will not be able to taste as well as us.
Our senses enable us to observe and detect changes in our surrounding, so that we can take care of ourselves.
Skin. Our skin allows us to feel and know its properties. We know whether an object is hard or soft, warm or cold, sharp or blunt when we touch it. It also protects us. When we feel pain, we will withdraw our body from the object. Anyone of you will let me pinch you and you do not feel any pain??
Eyes. Our eyes enable us to observe properties of an object. We know the colours, shapes and sizes. They also help use to count, recognize things and look for things. People who are blind have to make use of other senses to make up for their disadvantage.
Ears. Our ears enable us to distinguish sounds. Sounds can be pleasant or unpleasant, loud or soft, high or low pitched. Our eyes also tells us where sounds come from. That's why we also try to get our friends to talk to us so that we can find their hiding place when we play hide-and-seek.
Nose. Our nose distinguish pleasant and unpleasant smells. It warns us about changes in the environment. Would you want to eat something that smells really bad? You will also know when Mummy has something that is overcooked from the smell.
Tongue. Our tongue enable use to distinguish the four types of taste; sweet, sour, salty and bitter. People who pierce their tongue will not be able to taste as well as us.
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