Science Revision Notes

Dear all,

[Additional key points for Science]

P3 & P4 Revision

Light

• Light travels in a straight line. 
• A shadow is formed when an opaque objects block out the light path.
• Black and dark colours absorb heat very well while bright and lighter colours do not absorb heat very well. They reflect heat away. 
• Frosted glass, tinted glass are some of the objects that only partially block out light. 

Magnets

• Aluminium and copper are two of the metals that are not magnetic. 
• Steel and iron are two magnetic metals. 
• However, aluminium and copper allows magnetism to pass through it, so if you put a piece of aluminium sheet in between a magnet and a steel nail, they will still attract each other. 
• Magnetism is the strongest at the two ends of the magnet (Two poles).
• It is the weakest at the middle of the magnet. 
• There are three ways to form a magnet for magnetic materials - Electrical current, Stroking, Attraction (Touching) method. 
• Magnets can be found in items like telephone, radio, iron, rice cooker, etc. 

Heat

• Heat causes items to expand while cooling an item will cause it to contract. 
• Hot air rises, cold air condenses. 
• If two glass cups are stuck together, you can separate them by: a) putting one cup into hot water so that it expands or b)putting ice into one cup so that it contracts. 
• Boiling and evaporation are two processes which uses heat. 

Life Cycle

• Animals reproduce to ensure continuity of their own kind. 
• Animals with three stage life cycle - Grasshopper, Cockroach, Cricket, Frog. [ Egg -> Nymph -> Adult]
• Animals with four stage life cycle - Mosquito, butterfly, mealworm bettle, housefly. [ Egg -> Larva -> Pupa -> Adult]
• All mammals give birth to young alive with the exception of the anteater and the platypus which lay eggs.
• Amphibians can live both on land and in water, e.g Frog, Crocodile, tortoise. 

Additional P5 Revision notes

In addition to the notes I have gone through with you just now, here are some extra notes:

• All mammals fertilize internally except the platypus and anteater which lay eggs. 
• The womb is also known as the uterus. 
• DNA, genes and traits which are passed down from generations to generations, are stored in the nucleus of a cell.
• Note the functions and parts of a microscope!
• Certain plants cling onto poles, fences or branches of other trees for support as they have weak stems. This enables them to grow upwards to reach for sunlight. e.g morning glory.
• Overcrowding of plants means that plants will compete with each other for nutrients, water and sunlight. They grow very tall to compete for sunlight. 
• Remember that plants will grow towards the direction of the sunlight so even if i put a plant inside a clear glass box with a hole at the right hand side, it will still grow upwards vertically and not towards the hole!!!
• Only chloroplast/chlorophyll is present in the leaves of the plant!!!
• To make food, plants need sunlight, water and carbon dioxide and in turn, they give out glucose (sugar) and oxygen!
• Remember that in the day, plants take in carbon dioxide and give out oxygen but at night, plants give out carbon dioxide and take in oxygen.
• When there is no light, plants cannot photosynthesize and they take in oxygen and give out carbon dioxide. 
• Seeds need air, warmth and water to germinate. It does not need sunlight!!! Do not mix up with warmth with sunlight. 

And please read through my notes for you, your revision paper, topical worksheets and workbook!!! Look at the questions! 

Please highlight and use science concepts to answer your questions. Use scientific words like expand, contract, condense, evaporate, air can be compressed, definite shape, etc. This is what Science is about! Scientific concepts and words to answer your questions! Go for 40 and above / 60 for your MCQ! MCQ is where you can make a huge difference to your grades! Ace it and you will be on your way to pass and achieve a good band! 

All the best and please highlight key words!

Thank You,

Sincerely,

Mr Nelson Ong

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