Q&A - PSLE Science

[corneyAmber]

kitty2:

why the iron bridge need to be painted?

Thanks

So that it won't rust and change its property?

[corneyAmber]

underthesea:

I also want to know but don't know how. There's a mother I always speak to outside the school gate, she told me her dd has a way to do the science MCQ, she always score full marks if not just 1 wrong. I asked her to share, she said it's her dd's secret (??)...

Honestly, this mom is just proud and needs to brag. The honest truth is the child has innate abilities which she cannot even explain and probably the child is also an avid reader who reads widely.

I can only think of an exam-smart technique and that is to go by elimination method given 4 choices. Even that, a wealth of knowledge is required to do the elimination unless the teachers give obviously wrong possibilities which common sense will knock it off.

[leesf]

Hi, appreciate your help on the following question. Thanks

http://www.postimage.org/image.php?v=aVFBuSJ

[tutormum]

The key word in the question is "observe". The child is required to ans what he/she sees. Therefore (a) is "The balloon will deflate and the water level in the container will decrease". The reason is air takes up space, so when the thumb is released from the straw, air escapes from the balloon. The water will take the space left by the air and fill it up. (Another way of setting the question will be to explain what is observed.)

Ans to (b) is on similiar track. The difference in the amount of water in the balloon will decide the water level in the container. The concept learned is matter takes up space.
Hope my above explanation is clear. To score in Science, the child has to answer to the question and make use of what he/she has learnt and apply.
I agree with ksi on MCQ. The more well read a child is, the better he/she is able to answer MCQ accurately. Some MCQ are rather tricky so in order for a child to score well, he/she must be well versed in the concept learnt. Common sense does play a part to help the child make an intelligent guess when in doubt. This is probably the ‘secret’ the said mother is referring to.
For a child to do well in Science, textbook knowledge is not enough. A child has to be well exposed to Science and the world around him/her. The best way is to let the child watch documentaries relating to Science. It is fine for a child to watch certain ‘Science’ show such as Brainaic, Animal Night etc even though they may be 'out of syllabus". In the long run, your child will benefit as it also builds up his/her interest and confidence in Science.

[P5G]

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q1. Based only on the above diagram, what can be inferred from the fruit of plant Z?

A. Plant Z porduces flowers.

B. The fruit of plant Z is dispersed by wind.

C. The flesh of the fruit of plant Z is juicy and tasty.

D. The fibrous husk helps the fruit of plant Z to float.


(1) D only

(2) A and D only

(3) A, C and D only

(4) A, B, C and D only


My answer is (1) but the worksheet answer is (2). Which is correct?

TIA.

[P5G]

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q44 d) Explain whether it is a fair experiment to compare how well material P and Q conduct heat when Section X is longer than Section Y.

Worksheet answer: It is a fair experiment as we can check the distance of the nails A and B from the heat source is the same.

My answer: No. With a longer Section X, more heat will be lost at Section X and nail A will receive less heat than nail B.

Please advise which is correct?

TIA.

[P5G]

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q40 a) Which two mirrors can be removed so that no images of the ball are seen by the eye?


Worksheet answer: A and C.


My answer: B and C (or A and B).


Please advise which is correct?


TIA.

[P5G]

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-MGS.pdf


Q24.

Ericia carried out an experiment to compare the amount of water in 4 different vegetables. Firstly, she weighed the vegetables. Then she placed the vegetables out in the sun for a few days to dry them before weighing them again. She then recorded her results in the table below.

Please refer to the table in the worksheet.


Based on the above results, which of the following statement(s) is/are true of her experiment?

A. W has less water than Y.

B. X has as much water as W.

C. Z has the least amount of waater.

D. y has the greatest amount of water.


(1) A only

(2) B and C only

(3) A and D only

(4) A, B, C and D


Worksheet answer is (3).

My answer is (4).

Please advise which is correct.

TIA.

[Sun_2010]

P5G:

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q1. Based only on the above diagram, what can be inferred from the fruit of plant Z?

A. Plant Z porduces flowers.

B. The fruit of plant Z is dispersed by wind.

C. The flesh of the fruit of plant Z is juicy and tasty.

D. The fibrous husk helps the fruit of plant Z to float.


(1) D only

(2) A and D only

(3) A, C and D only

(4) A, B, C and D only


My answer is (1) but the worksheet answer is (2). Which is correct?

TIA.

Since there is a fruit, the plant must be a flowering plant.
Hence A is also correct.

[Sun_2010]

P5G:

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q44 d) Explain whether it is a fair experiment to compare how well material P and Q conduct heat when Section X is longer than Section Y.

Worksheet answer: It is a fair experiment as we can check the distance of the nails A and B from the heat source is the same.

My answer: No. With a longer Section X, more heat will be lost at Section X and nail A will receive less heat than nail B.

Please advise which is correct?

TIA.

As long as the nails are place at equal distnce from the heat source , the experiment is fair.

Just say that material P and Q are the same, then wont the temperature at A and B be same?