2011 PSLE Discussions and Strategy

[wkong]

tisha:

http://i56.tinypic.com/10wvfiv.jpg\">


This Q is from Pei Chun Prelim 2011, it is Q18.
Need help with the correct answer. The ans key( by Jeremy) says 3. But DS says the answer is 1. :?

Hi tisha,

I checked with the sch teacher and here is what he explained:

The answer is (3). Look at the calibration on the measuring cylinder. Since, oxygen takes up 20% of the composition of air, the water should only rise up by 20%.

Hope this helps.

Cheers,
wkong

[Brenda10]

Hi, the last supplementary class for DD will be on next Thursday (22/9).


Think the school wants to release them as per normal school hours before the 1st written exam on 29/9.

[Tinkerbelle]

Brenda10:

Hi, the last supplementary class for DD will be on next Thursday (22/9).


Think the school wants to release them as per normal school hours before the 1st written exam on 29/9.

Hi Brenda,
DD's sch last supp lesson is next Friday (23/9). I'm glad that's no supp during the PSLE week. Can ease the pressure off the kids a little.

[Brenda10]

Tinkerbelle:

Brenda10:

Hi, the last supplementary class for DD will be on next Thursday (22/9).


Think the school wants to release them as per normal school hours before the 1st written exam on 29/9.

Hi Brenda,
DD's sch last supp lesson is next Friday (23/9). I'm glad that's no supp during the PSLE week. Can ease the pressure off the kids a little.

Hi Tinkerbelle,

Yes, think the intention is for them to have good rest and get ready for the Big Day!

[Brenda10]

Tinkerbelle:

Brenda10:

Hi, the last supplementary class for DD will be on next Thursday (22/9).


Think the school wants to release them as per normal school hours before the 1st written exam on 29/9.

Hi Brenda,
DD's sch last supp lesson is next Friday (23/9). I'm glad that's no supp during the PSLE week. Can ease the pressure off the kids a little.

Hi Tinkerbelle,

Yes, think the intention is for them to have good rest and get ready for the Big Day!

[Tinkerbelle]

Brenda10:

Tinkerbelle:

[quote=\"Brenda10\"]Hi, the last supplementary class for DD will be on next Thursday (22/9).


Think the school wants to release them as per normal school hours before the 1st written exam on 29/9.

Hi Brenda,
DD's sch last supp lesson is next Friday (23/9). I'm glad that's no supp during the PSLE week. Can ease the pressure off the kids a little.

Hi Tinkerbelle,

Yes, think the intention is for them to have good rest and get ready for the Big Day! [/quote]Hi Brenda,

Lovely avatar!

Agree....a good rest is definitely needed prior to PSLE. Must have a clear mind for their 1st national exams. :idea:

[Brenda10]

Tinkerbelle:

Hi Brenda,


Lovely avatar!

Agree....a good rest is definitely needed prior to PSLE. Must have a clear mind for their 1st national exams. :idea:

Hi Tinkerbelle,

Thank you!

Yes, 1st national exam in their life!

BTW, heard from dd the school will be returning all the P6 Record Books these two days.

[Ms tay]

tisha:

http://i56.tinypic.com/10wvfiv.jpg\">


This Q is from Pei Chun Prelim 2011, it is Q18.
Need help with the correct answer. The ans key( by Jeremy) says 3. But DS says the answer is 1. :?

Hi tisha,

The answer is 3, cuz after a week, the iron should have rusted when it reacted with the condensed water vapour and oxygen in the tube. As we know, rusting is oxidization and oxidization 'absorbs' the oxygen in the tube. Thus, the amount of air in the tube will be reduced slightly, allowing more space for the water to fill in, resulting in a rise in water level in the tube. However, this contradicts the theory that water level is always equal, but the reason that the water level is not equal and the water level in the tube is higher than the water level in the basin becuz when the air in the tube is reduced, air pressure in the tube will decrease, so the outside air will push the water into the tube from the basin to equalize the air pressure. Besides, 21% of atmospheric air is oxygen, so the water level should increase by roughly 21%, and option 3 depicts this happening. Wish my answers is helpful...

[Tinkerbelle]

Brenda10:

Tinkerbelle:

Hi Brenda,


Lovely avatar!

Agree....a good rest is definitely needed prior to PSLE. Must have a clear mind for their 1st national exams. :idea:

Hi Tinkerbelle,

Thank you!

Yes, 1st national exam in their life!

BTW, heard from dd the school will be returning all the P6 Record Books these two days.

Hi Brenda,
Really?? The P6 get their report books so soon? Guess the sch needs to inform parents the official prelim results before PSLE so everyone will have a better idea of where they stand. Hope DD get hers soon too.

[tisha]

wkong:

tisha:

This Q is from Pei Chun Prelim 2011, it is Q18.
Need help with the correct answer. The ans key( by Jeremy) says 3. But DS says the answer is 1. :?

Hi tisha,

I checked with the sch teacher and here is what he explained:

The answer is (3). Look at the calibration on the measuring cylinder. Since, oxygen takes up 20% of the composition of air, the water should only rise up by 20%.

Hope this helps.

Cheers,
wkong

Thanks for the explaination wkong. Will explain to DS.