Q&A - PSLE Science

[pertunia]

And also why answers (A) and (B) are incorrect?

Animals include insects too right? Pls enlighten me. Thanks.

[Happygolucky]

I have a question from 2011 Catholic High Prelim 2, question 41.

It came with a picture but I have no idea how to post picture. Nonetheless, the question is as follows:

Steve wanted to test the properties of water and air. He placed 2 balloons of the same types, one completely filled with air only and the other completely filled with water and placed them over a candle flame. He lit the candle and observed what happened.

he recorded the time take for the balloon to pop.
Set up A(the one filled with air): 2 sec
Set up B(the one filled with water): 200s

(a) What can you conclude about the property of water based on the experiment?(1 mark)
(b) Explain the difference in time taken for the balloons to pop.(2 marks)
State a variable that he must keep constant to conduct a fair test.(1 mark)

[jewelbox]

Hi, appreciate any help to ans the 2 qns related to magnet. Thanks. http://i45.tinypic.com/9bkhfd.jpg\">

[jewelbox]

here is the other one: http://i47.tinypic.com/dr94z.jpg\">

[kiasuaunt]

jewelbox:

here is the other one: http://i47.tinypic.com/dr94z.jpg\">

Hi - I hv the ans as it is my dd's school paper - the ans is 1.

[jewelbox]

thanks kiasuaunt, you are fast:)

[kiasuaunt]

jewelbox:

thanks kiasuaunt, you are fast:)

You r most welcome - is the other question from the same school ? I can search the ans for u if it is.

[Sun_2010]

jewelbox:

Hi, appreciate any help to ans the 2 qns related to magnet. Thanks. http://i45.tinypic.com/9bkhfd.jpg\">

Ans 3

[BeContented]

DS says all along his understanding is :


During germination, oxygen, water & warmth is required.
But his Mindstretcher teacher says that during germination, oxygen is not required. Only when the leaves start then oxygen is required.

Errhhh…now he’s confused. Anyone can help confirm?

[Little Einstein]

BeContented:

DS says all along his understanding is :


During germination, oxygen, water & warmth is required.
But his Mindstretcher teacher says that during germination, oxygen is not required. Only when the leaves start then oxygen is required.

Errhhh....now he's confused. Anyone can help confirm?

Oxygen is definitely needed. How come Mindstretcher teaches him the wrong concept!
It is just that sunlight is needed when the first leaves appeared.

I am the main science tutor in my centre and i have been teaching Science for the last 12 years! Such mistake cannot be made! :mad: